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The main objective of this paper is to investigate the impact of f(Q,T)$f(\mathcal {Q},\mathcal {T})$ gravity on the geometry of anisotropic compact stellar objects, where Q$\mathcal {Q}$ is non‐metricity and T$\mathcal {T}$ is the trace of the energy‐momentum tensor. In this perspective, the physically viable non‐singular solutions to examine the configuration of static spherically symmetric structures is used. A specific model of this theory to examine various physical quantities in the interior of the proposed compact stars (CSs) is considered. These quantities include fluid parameters, anisotropy, energy constraints, equation of state parameters, mass, compactness, and redshift. The Tolman–Oppenheimer–Volkoff equation is used to examine the equilibrium state of stellar models, while the stability of the proposed CSs is investigated through sound speed and adiabatic index methods. It is found that the proposed CSs are viable and stable in the context of this theory. The main objective of this paper is to investigate the impact of f(Q,T)$f({\mathcal{Q},\mathcal{T}})$ gravity on the geometry of anisotropic compact stellar objects, where Q$\mathcal{Q}$ is non‐metricity and T$\mathcal{T}$ is the trace of the energy‐momentum tensor. In this perspective, the physically viable non‐singular solutions to examine the configuration of static spherically symmetric structures is used. A specific model of this theory to examine various physical quantities in the interior of the proposed compact stars (CSs) is considered. These quantities include fluid parameters, anisotropy, energy constraints, equation of state parameters, mass, compactness, and redshift. The Tolman–Oppenheimer–Volkoff equation is used to examine the equilibrium state of stellar models, while the stability of the proposed CSs is investigated through sound speed and adiabatic index methods. It is found that the proposed CSs are viable and stable in the context of this theory. [ABSTRACT FROM AUTHOR]

In this paper, both fundamental SSP modes on a roofed metallic grating and its effective excitation of the bounded SSP mode by an injected electron beam on the structure are numerically examined and investigated in the THz regime. Apart from the bounded SSP mode on the metallic grating with open space, the introduced roofed metallic grating can generate a closed waveguide mode that occupies the dispersion region outside the light line. The closed waveguide mode shifts gradually to a higher frequency band with a decreased gap size, while the bounded SSP mode line becomes lower. The effective excitation of the bounded SSP mode on this roofed metallic grating is also implemented and studied by using a particle-in-cell simulation studio. The output SSP power spectrums with various gap sizes by the same electron beam on this roofed metallic grating are obtained and analyzed. The simulation results reveal that the generated SSP spectra show a slight red shift with a decreased gap size. This work on the excitation of the SSP mode using an electron beam can benefit the development of high-power compact THz radiation sources by utilizing the strong near-field confinement of SSPs on metallic gratings. [ABSTRACT FROM AUTHOR]

In this paper we present the Spitzer IRS low-resolution observation for four candidates of Seyfert 1-like objects of ULIRGs from the SDSS-2dF-6dF sample. It is found that they are all real Seyfert 1-like objects because their infrared spectra are similar to that for Seyfert 1 source indicative of AGN nature, i.e. their spectra all show high-ionization lines of [NeV] at 14.32 μm and/or [SIV] at 10.51 μm in the mid-infrared. On the other hand, it is found that they also show PAH features at 6.2, 7.7, 8.6 and 11.25 μm indicative of star formation activity. In addition, it is found that they all show the silicate feature in absorption around 10 μm indicative of heavily material obscured these sources. Furthermore, some correlations among the far infrared colors, the line ratios, the equivalent widths (EWs) of PAH feature and the Silicate strengths are also discussed for these sources. [ABSTRACT FROM AUTHOR]

In several practical sectors, it has been demonstrated that multistate emissive materials have far wider applications than single state emissive fluorophore materials; yet, this remains an extremely challenging undertaking. It has been thought that adding rigid and twisted moieties to the D-A-D core will be appropriate to allow for both solid state and solution emission. By developing a donor-acceptor-donor pattern in a twisted molecule, herein we design and synthesize triphenylamine based two novel luminogens MSE1 and MSE2 with dual-state emission (DSEgens) which are brilliantly luminous equally at the liquid and solid phase, with positive solvatochromic features. The triphenylamine molecule's bulkiness can limit intramolecular movement in the liquid phase, thereby diminishing the non-radiative emission. Additionally, the twisted structure of the molecule reduce the negative effects of close π-π stacking in the solid state resulting high emission at aggregated state. In poor solvent like H 2 O and extremely condensed solvent like polyethylene glycol, compound MSE1 and MSE2 exhibit aggregation-caused redshift emission (ACRE), which are supported by DLS and SEM investigations. The compound MSE1 in THF solution is able to recognize mercury selectively over other competitive cation through UV–vis and fluorescence channel. An eight fold suppression of fluorescence intensity and a change in absorbance of 115 nm were noted at the addition of 0–8 equivalent mercury to MSE1. Additionally, MSE1 has been used to create a low-cost, portable test paper strip that may be used to selectively monitor mercury in real time. [Display omitted] • Two triphenylamine based luminogens were synthesized by introducing partially shared donor-accepter-donor pattern. • These luminogens could be employed as both solution and solid state emissive material. • These luminogens have been observed to possess a positive solvachromism behavior. • At higher fraction of H 2 O/PEG, these molecules exhibit Aggregation-Caused Red Shifted Emission. • The molecule has the ability to selectively detect hazardous mercury ions in both colorimetric and fluorometric channels. [ABSTRACT FROM AUTHOR]

Narrowband optical absorption plays a key role in photonic sensors and photovoltaic elements. Here, we propose a design of creating narrowband absorbers based on the symmetric and asymmetric defective photonic crystals (SDPCs and ADPCs) consisting of defects in the form of DMD in which M indicates the WS2 or WSe2 monolayer and D represents the SiO2 layer. In this paper, the effect of the defect layer thickness, polarization, and incident angle of light on the number and wavelength of defect modes in both symmetric and asymmetric structures is investigated. The findings suggest that the wavelength of the defect modes can be adjusted by varying the thickness of layer D as well as the design of the wavelength and tuned by polarization and incident angle of light. In both SDPC and ADPC, the wavelength of the defect mode shows red shift with an increase in the thickness of layer D and exhibits blue shift with an increase in the angle of light in both TE and TM polarization. This narrowband absorber demonstrates great potential for being adopted in the detection of photodetectors, absorbent filters, and the like. [ABSTRACT FROM AUTHOR]

In this paper, we examine the stability condition of f(T) gravity theory where T is the Torsion scalar using interacting and non-interacting models with the help of dynamical system. We let the f(T) function be f(T)=αT+β, where T is Torsion scalar and α and β are the arbitrary constants. We calculated the critical points and study the stability behavior for this model. We analyze the system’s phase graphs and examined the physical interpretation. We demonstrate all of the cosmological parameters including Ωm, Ωϕ, q, and ωTot at each critical point and contrast them with values from observations. Then, we assume hybrid scale factor and transform it into the equation of redshift and time. Using this equation, we convert all the parameters into terms of redshift and analyze their behavior. Our model illustrates the Universe’s accelerating expansion. The energy conditions are examined in terms of redshift for the model. As a result, we conclude that our f(T) model is stable and all the observed values are in agreement with observations. [ABSTRACT FROM AUTHOR]

This paper explores isotropic polytropes within the framework of the f(R,G) modified gravity theory. We derive the field equations that govern these systems and develop the Lane–Emden equations for both mass (baryonic) density and total energy density, utilizing two different polytropic equations of state. Our analysis shows that the constructed models feature positive and finite density and pressure, which decrease as expected towards the outer boundary, aligning with the typical behavior of self-gravitating objects. Additionally, the energy–momentum tensor meets the required energy conditions, confirming the physical viability of the models. The compactness factor remains below the critical limit, signifying stability and providing insights into gravitational redshift. Analysis of the sound speed confirms adherence to causality, while the adiabatic index indicates a degree of stiffness within the system. These findings advance our understanding of self-gravitating objects in f(R,G) gravity and lay the groundwork for future research in this field. [ABSTRACT FROM AUTHOR]

A series of heteroleptic copper(I) β-diketiminate triarylphosphine complexes is reported, having the general formula Cu(R¹NacNacR2)(PPhX3), where R¹NacNacR2 is a substituted β-diketiminate and PPhX3 is a triphenylphosphine derivative. A total of five different R¹NacNacR2 ligands and three different triarylphosphines are used to assemble the nine complexes. The syntheses, X-ray crystal structures, cyclic voltammograms, and UV–vis absorption spectra of all compounds are described. Whereas most of the compounds are weakly luminescent or only luminesce at 77 K, the four complexes with the more sterically encumbered β-diketiminate ligands, with methyl or isopropyl substituents at the 2- and 6-positions of the N-phenyl rings, exhibit weak room-temperature photoluminescence with peaks between 519 and 566 nm and long excited-state lifetimes in the range of 15–70 μs. The sterically encumbering substituents in this subset have subtle effects on the UV–vis absorption maximum, which red shifts slightly as the steric bulk increases, as well as significant effects on the photoluminescence lifetime, which is observed to increase as the steric bulk is augmented. Substituents on the triarylphosphine also influence the excited-state dynamics in the bulky complexes, with the more electron-rich tris(4-methoxyphenyl)phosphine (PPhOMe3) giving longer-excited-state lifetimes compared to triphenylphosphine (PPh3) when the same R¹NacNacR2 ligand is used. [ABSTRACT FROM AUTHOR]

Cosmological analyses using galaxy clusters in optical/near-infrared photometric surveys require robust characterization of their galaxy content. Precisely determining which galaxies belong to a cluster is crucial. In this paper, we present the CO lor P robabilistic A ssignment of C lusters A nd BA yesia NA nalysis (Copacabana) algorithm. Copacabana computes membership probabilities for all galaxies within an aperture centred on the cluster using photometric redshifts, colours, and projected radial probability density functions. We use simulations to validate Copacabana and we show that it achieves up to 89 per cent membership accuracy with a mild dependence on photometric redshift uncertainties and choice of aperture size. We find that the precision of the photometric redshifts has the largest impact on the determination of the membership probabilities followed by the choice of the cluster aperture size. We also quantify how much these uncertainties in the membership probabilities affect the stellar mass–cluster mass scaling relation, a relation that directly impacts cosmology. Using the sum of the stellar masses weighted by membership probabilities (⁠|$\rm \mu _{\star }$|⁠) as the observable, we find that Copacabana can reach an accuracy of 0.06 dex in the measurement of the scaling relation at low redshift for a Legacy Survey of Space and Time type survey. These results indicate the potential of Copacabana and |$\rm \mu _{\star }$| to be used in cosmological analyses of optically selected clusters in the future. [ABSTRACT FROM AUTHOR]

PKS 1351-018 at a redshift of z = 3.71 is one of the most luminous, steady synchrotron sources with a luminosity >1047 erg s−1. The synchrotron luminosity does not seem to have varied by more than ∼25% over 35 yr. In order to appreciate this remarkable behavior, if it were at z = 0.5, it would have a flux density at 15 GHz in a range of 110–137 Jy over 11 yr. In spite of this steady behavior, two strong γ-ray flares ≲1049 erg s−1 were detected in 2011 and 2016. There is a blazar-like behavior coexisting with the steady behavior. This study is aimed at elucidating the dual nature of this source. We find that the radio source is extremely compact with a bright core and a steep spectrum secondary component, 12 mas away, that appears to be constant in position and flux density in six epochs from 1995–2018. We estimate that a jet with a time averaged power of (5.2 ± 3.2) × 1045 erg s−1 terminates in this lobe, which is advancing ≳0.9c at a deprojected distance of 1–3 kpc from the central engine. This is the rare case of a young (∼6000 yr), very powerful radio source that is viewed a few degrees from the jet axis. We find evidence of a high velocity (4000 km s−1), high ionization wind emanating from a luminous quasar. The young radio jet appears to experience modest bending as it navigates through the intense quasar environment. [ABSTRACT FROM AUTHOR]

Herein, a colorimetric sensor (L) based on a naphthyl derivative bearing hydrazone receptors was synthesized via a one-step reaction process, and its recognition properties towards biologically important anions in an acetonitrile–water mixture were investigated by naked-eye observation and UV-Vis and 1H NMR spectroscopy. The molar addition of anions, such as TBAF−, TBAOH−, TBACN− and TBAAcO−, induced a significant red shift in the charge transfer band (Δλ = 73 nm, from 337 nm to 410 nm), in agreement with visible "naked eye" detectable colorimetric activities; in addition, soaked-in-L paper strips were prepared, which could significantly discriminate cyanide (KCN) and hydroxide (NaOH) ions dissolved in tap water via the litmus test method. This study was complemented by density functional theory computations to gain more insight into the interaction between L and anions. [ABSTRACT FROM AUTHOR]

This paper develops the stellar interior geometry for charged anisotropic spherical matter distribution by developing an exact solution of the field equations of Rastall gravity using the notion of gravitational decoupling. The main purpose of this investigation is the extension of the well-known isotropic model within the context of charged isotropic Rastall gravity solutions. The second aim of this work is to apply gravitational decoupling via a minimal geometric deformation scheme in Rastall gravity. Finally, the third one is to derive an anisotropic version of the charged isotropic model previously obtained by applying gravitational decoupling technology. We construct the field equations which are divided into two sets by employing the geometric deformation in radial metric function. The first set corresponds to the seed (charged isotropic) source, while the other one relates the deformation function with an extra source. We choose a known isotropic solution for spherical matter configuration including electromagnetic effects and extend it to an anisotropic model by finding the solution of the field equations associated with a new source. We construct two anisotropic models by adopting some physical constraints on the additional source. To evaluate the unknown constants, we use the matching of interior and exterior spacetimes. We investigate the physical feasibility of the constructed charged anisotropic solutions by the graphical analysis of the metric functions, density, pressure, anisotropy parameter, energy conditions, stability criterion, mass function, compactness, and redshift parameters. For the considered choice of parameters, it is concluded that the developed solutions are physically acceptable as all the physical aspects are well-behaved. [ABSTRACT FROM AUTHOR]

The hard X-ray emission in active galactic nuclei (AGN) and black hole X-ray binaries is thought to be produced by a hot cloud of electrons referred to as the corona. This emission, commonly described by a power law with a high-energy cutoff, is suggestive of Comptonization by thermal electrons. While several hypotheses have been proposed to explain the origin, geometry, and composition of the corona, we still lack a clear understanding of this fundamental component. NuSTAR has been playing a key role improving our knowledge of X-ray coronæ thanks to its unprecedented sensitivity above 10 keV. However, these constraints are limited to bright, nearby sources. The High Energy X-ray Probe (HEX-P) is a probe-class mission concept combining high spatial resolution X-ray imaging and broad spectral coverage (0.2-80 keV) with a sensitivity superior to current facilities. In this paper, we highlight the major role that HEX-P will play in further advancing our insights of X-ray coronæ notably in AGN. We demonstrate how HEX-P will measure key properties and track the temporal evolution of coronæ in unobscured AGN. This will allow us to determine their electron distribution and test the dominant emission mechanisms. Furthermore, we show how HEX-P will accurately estimate the coronal properties of obscured AGN in the local Universe, helping address fundamental questions about AGN unification. In addition, HEX-P will characterize coronæ in a large sample of luminous quasars at cosmological redshifts for the first time and track the evolution of coronæ in transient systems in real time. We also demonstrate how HEX-P will enable estimating the coronal geometry using spectral-timing techniques. HEX-P will thus be essential to understand the evolution and growth of black holes over a broad range of mass, distance, and luminosity, and will help uncover the black holes' role in shaping the Universe. [ABSTRACT FROM AUTHOR]

Brane world models have shown to be promising to understand the late cosmic acceleration, in particular because such acceleration can be naturally derived, mimicking the dark energy behaviour just with a five dimensional geometry. In this paper we present a strong lensing joint analysis using a compilation of early-type galaxies acting as a lenses, united with the power of the well studied strong lensing galaxy cluster Abell 1689. We use the strong lensing constraints to investigate a brane model with variable brane tension as a function of the redshift. In our joint analysis we found a value n = 7. 8 - 0.5 + 0.9 , for the exponent related to the brane tension, showing that n deviates from a Cosmological Constant (CC) scenario (n=6). We obtain a value for the deceleration parameter, q(z) today, q (0) = - 1. 2 - 0.8 + 0.6 , and a transition redshift, z t = 0.60 ± 0.06 (when the Universe change from an decelerated phase to an accelerated one). These results are in contrast with previous work that favors CC scenario, nevertheless our lensing analysis is in agreement with a formerly reported conclusion suggesting that the variable brane tension model is able to source a late cosmic acceleration without an extra fluid as in the standard one. [ABSTRACT FROM AUTHOR]

On the road towards observational (and experimental) validation of the DEUS cosmological model we will cross the boundary between theory and observation with the help of Hubble's law for the Universe evolution, expressed as function of quantities as redshift z (measured through Doppler-shift observations) and local time T. In the book by Popescu (2007) we gave a theoretical method for computing the Hubble constant H0. Now, in the light of the new acquired knowledge that followed Popescu (2020) paper's results, after defining what is the local time for the flat spacetime and how it relates to the FLRWspacetime, we will be able to derive the Hubble's law H (T). The theoretical meaning of the redshift parameter contained by it will diverge from the one given by the classical expansion cosmological models, not being directly dependant on the time T (or age of the Universe), but rather on the way the entropy evolved in the Universe, at some particular location, with the tFLRW time. [ABSTRACT FROM AUTHOR]

In this paper, the structural, electrical and optical effects of WS2 doped with silicon atoms after torsional deformation are investigated using first-principles calculations. First-principles calculations for metal disulfide-WS2. The doping of Si atoms gives WS2 a tunable band gap, and the surface state is successfully transformed from a 2.0 eV band gap to a quasi-metal with a 0.254 eV band gap, and the change of the doped Si atoms causes a redshift in the absorption peak and a blueshift in the reflection peak. The band gap of WS2 can be effectively adjusted by torsional deformation on the basis of Si-doped atoms in the range 0.254–0.052 eV. Calculations of optical properties show that Si-doped WS2 with a torsion angle of 1 0 ∘ has the lowest light absorption peak and Si-doped WS2 with a torsion angle of 8 ∘ has the lowest light reflection peak. This paper opens up new possibilities for designing materials on demand. [ABSTRACT FROM AUTHOR]

In this paper, Φ25 mm lanthanum bromide scintillation crystals with 5%Ce3+ and different Sr2+ doping concentrations (0.1%, 0.3%, 0.5% in molar ratio) were successfully grown by spontaneous nucleation vertical Bridgman method. X-ray excited emission spectra, transmission spectra and pulse height spectra of these crystals were measured. Results show that, the emission spectra waveform of LaBr3:Ce crystals with different Sr2+ doping concentrations is basically consistent under X-ray excitation, and the emission peak shows a significant red shift compared with that of sample without Sr2+ doping. With the increase of Sr2+ doping concentration, the emission peak of LaBr3:Ce,Sr crystal shows a slight red shift. There is no obvious absorption peak range from 350 to 800 nm of LaBr3:Ce,Sr crystals with different Sr2+ doping concentrations. Compared with LaBr3:Ce crystals, transmittance of 0.3% and 0.5% Sr2+ doped LaBr3:Ce crystals decrease. In addition, with the increase of Sr2+ doping concentration, the energy resolution of the crystal increases correspondingly. LaBr3:Ce,0.5% Sr crystal has the highest energy resolution of 2. 99%@662 keV. The energy resolution of the encapsulated LaBr3:Ce,0.5%Sr crystal with size of Φ25 mm x 25 mm is 2.93%@662 keV. [ABSTRACT FROM AUTHOR]

This paper shows that a simple and relativistic extension of Newtonian gravity that takes into account Lorentz relativistic mass leads to predictions that fit supernova observations of magnitude versus redshift without the need to introduce dark energy. To test the concept, we look at 580 supernova data points from the Union2 database. Some relativistic extensions of Newtonian gravity have been investigated in the past, but we have reason to believe the efforts were rejected prematurely before their full potential was investigated. Our model suggests that mass, as related to gravity, is also affected by Lorentz relativistic effects, something that is not the case in standard gravity theory, and this adjustment gives supernova predictions that fit the observations. Our model seems very robust with respect to supernova data, as no arbitrary parameters are introduced. Since recent investigations of Lorentz's relativistic mass also seem to solve other challenges in physics, we think it is worthwhile for the physics community to look into this more carefully, at least before rejecting it based on prejudice. After all, no one has been able to detect dark energy despite massive efforts to do so. Until dark energy is really confirmed, other alternative models should be worth investigating further. [ABSTRACT FROM AUTHOR]

Relativistically broadened and redshifted 6.4–6.9 keV iron K lines are observed from many accretion powered objects, including X-ray binaries and active galactic nuclei. The existence of gas close to the central engine implies large radiation intensities and correspondingly large gas densities if the gas is to remain partially ionized. Simple estimates indicate that high gas densities are needed to allow for the survival of iron against ionization. These are high enough that rates for many atomic processes are affected by mechanisms related to interactions with nearby ions and electrons. Radiation intensities are high enough that stimulated processes can be important. Most models currently in use for interpreting relativistic lines use atomic rate coefficients designed for use at low densities and neglect stimulated processes. In our work so far we have presented atomic structure calculations with the goal of providing physically appropriate models at densities consistent with line-emitting gas near compact objects. In this paper we apply these rates to photoionization calculations, and produce ionization balance curves and X-ray emissivities and opacities that are appropriate for high densities and high radiation intensities. The final step in our program will be presented in a subsequent paper in which model atmosphere calculations will incorporate these rates into synthetic spectra. [ABSTRACT FROM AUTHOR]

In this paper, we present a method to compute the x-ray absorption near-edge structure (XANES) spectra of solid-state transition metal oxides using real-time time-dependent density functional theory, including spin–orbit coupling effects. This was performed on bulk-mimicking anatase titania (TiO2) clusters, which allows for the use of hybrid functionals and atom-centered all electron basis sets. Furthermore, this method was employed to calculate the shifts in the XANES spectra of the Ti L-edge in the presence of applied electric fields to understand how external fields can modify the electronic structure, and how this can be probed using x-ray absorption spectroscopy. Specifically, the onset of t2g peaks in the Ti L-edge was observed to red shift and the eg peaks were observed to blue shift with increasing fields, attributed to changes in the hybridization of the conduction band (3d) orbitals. [ABSTRACT FROM AUTHOR]

We report the vibrational energy levels of vinyl radical (VR) that are computed with a Lanczos eigensolver and a contracted basis. Many of the levels of the two previous VR variational calculations differ significantly and differ also from those reported in this paper. We identify the source of and correct symmetry errors on the potential energy surfaces used in the previous calculations. VR has two equivalent equilibrium structures. By plotting wavefunction cuts, we show that two tunneling paths play an important role. Using the computed wavefunctions, it is possible to assign many states and thereby to determine tunneling splittings that are compared with their experimental counterparts. Our computed red shift of the hot band at 2897.23 cm−1, observed by Dong et al. [J Chem. Phys. 128, 044305 (2008)], is 4.47 cm−1, which is close to the experimental value of 4.63 cm−1. [ABSTRACT FROM AUTHOR]

In this paper, we present a simple toy model for a possible Ricci–Gauss–Bonnet gravity universe in which a novel form of cyclic evolution occurs where the Hubble parameter remains positive and oscillates. In this model, we have used the form for f(R,풢) gravity as αR + β풢2. In order to simulate cosmic transit, we have considered a time-dependent deceleration parameter oscillating in between the two phases of deceleration and acceleration which leads to a specific form for the Hubble parameter. The current periodic model predicts the deceleration–acceleration cosmic transit to happen at approximately 8.7Gyr. The evolution of different parameters with the redshift has been plotted and analyzed. The contributions of the entropy-corrected holographic dark energy and the modified holographic Ricci dark energy density to the total energy parameter have been investigated. [ABSTRACT FROM AUTHOR]

A new series of β-functionalized meso-tetraphenylporphyrins bearing 4-methoxyphenyl, 3,5-dimethoxyphenyl and 3,4,5-trimethoxyphenyl groups appended selectively to the single pyrrole unit of the porphyrin macrocycle, H2TPPR2 (where R = p-CH3O-Ph, m-CH3O-Ph and m,p-CH3O-Ph), and their Co(II), Ni(II), Cu(II) and Zn(II) metal complexes were synthesized, characterized and meticulously examined for their adjustable electronic spectral, electrochemical and structural attributes. A gradual bathochromic shift of absorption bands (Δλmax = 5–8 nm) was observed in these porphyrins relative to the unsubstituted parent porphyrin, H2TPP. A progressive cathodic shift in the first ring oxidation potential was observed in the series. Among all free base porphyrins, H2TPP(p-CH3O-Ph)2 showed the maximum red shifted absorption and the largest cathodic shift in the first ring oxidation, unveiling the effective electron donation via the +R effect of methoxy groups placed at the para position of β-phenyl rings. Within this framework, fine-tuning of the HOMO–LUMO gap accompanied by a gradual reduction in energy was observed which followed the trend H2TPP(m,p-CH3O-Ph)2 (2.22 V) > H2TPP(m-CH3O-Ph)2 (2.13 V) > H2TPP(p-CH3O-Ph)2 (2.08 V). Single crystal X-ray analyses of H2TPP(p-CH3O-Ph)2, ZnTPP(m-CH3O-Ph)2 and CuTPP(m-CH3O-Ph)2 unfolded planar, quasi-planar and saddle conformations respectively. Hirshfeld surface and 2D fingerprint plot analysis were also performed to see the significant intermolecular interactions. Further, DFT and TDDFT calculations were performed to gain a deeper understanding of the observed experimental results. [ABSTRACT FROM AUTHOR]

In this paper, we present the construction and analysis of an interior solution for a compact star in Rastall gravity. The space–time considered is static and spherically symmetric, meanwhile, the source of matter is that of a perfect fluid. The solution of the equations system which describes the model is obtained from a specific form of the red shift factor function and its result is physically acceptable. The analysis of the solution is focused on the description of the star PSR J 0 3 4 8 + 0 4 3 2 , for which we know the observational data of mass M = (2. 0 1 ± 0. 0 4) M ⊙ and radius R = (1 2. 5 0 9 5 ± 0. 4 4 7 5) km, a comparison with the behavior of the solution in the frame of Einstein's general relativity theory, λ = 1 , shows that for λ > 1 the density, pressure and speed of sound are greater, meanwhile for λ < 1 their values are lower. The analysis of the generalized TOV equation to the case of the Rastall gravity implies that the contribution of the force associated to the Rastall parameter can generate an attractive (λ > 1) or repulsive (λ < 1) force, showing the relevance and the effect that the Rastall parameter has in stellar models. [ABSTRACT FROM AUTHOR]

In this paper, we present an extensive analysis of SN 2021 wuf, a transition between Ia-norm and SN 1991T-like supernovae, which exploded at the periphery of the tidal bridge between the pair galaxy NGC 6500 and NGC 6501, at a redshift of z = 0.01. Our observations, ranging from −21 to +276 days relative to the B-band maximum light, reveal that SN 2021wuf exhibits properties akin to normal SNe Ia, with a peak absolute magnitude of Mmax(B)  ∼   − 19.49  ±  0.10 mag and a post-peak decline rate of Δm15(B)  ∼  1.11  ±  0.06 mag. The peak bolometric luminosity of this SN is estimated as 1.58  × 1043 erg s−1, corresponding to a 56Ni mass of MNi  ∼  0.64  ±  0.05 M⊙. The spectral features, including high-velocity Si IIλ6355 lines, a plateau in the Si IIλ6355 velocity evolution and the nickel-to-iron ratio in the nebular phase, suggest a potential pulsating delayed detonation mechanism. The absence of intermediate-mass elements in the early phase and the high photospheric temperature, as inferred from the line-strength ratio of Si IIλ5972 to Si IIλ6355 (named as R(Si II)), further support this classification. [ABSTRACT FROM AUTHOR]

A dedicated gamma-ray burst (GRB) afterglow observing program was performed between 2007 and 2016 with GROND, a seven-channel optical and near-infrared imager at the 2.2m telescope of the Max-Planck Society at ESO/La Silla, In this first of a series of papers, we describe the GRB observing plan, providing first readings of all so far unpublished GRB afterglow measurements and some observing statistics. In total, we observed 514 GRBs with GROND, including 434 Swift-detected GRBs, representing 81% of the observable Swift sample. For GROND-observations within 30 min of the GRB trigger, the optical/NIR afterglow detection rate is 81% for long- and 57% for short-duration GRBs. We report the discovery of ten new GRB afterglows plus one candidate, along with redshift estimates (partly improved) for four GRBs and new host detections for seven GRBs. We identify the (already known) afterglow of GRB 140209A as the sixth GRB exhibiting a 2175 Å dust feature. As a side result, we identified two blazars, with one at a redshift of z = 3.8 (in the GRB 131209A field). [ABSTRACT FROM AUTHOR]

In this paper, we present rapid follow-up observations of the short GRB 201006A, consistent with being a compact binary merger, using the LOw Frequency ARray (LOFAR). We have detected a candidate 5.6 |$\sigma$|⁠ , short, coherent radio flash at 144 MHz at 76.6 min post-GRB with a 3 |$\sigma$| duration of 38 s. This radio flash is 27 arcsec offset from the GRB location, which has a probability of being co-located with the GRB of |$\sim$| 0.05 per cent (3.8 |$\sigma$|⁠) when accounting for measurement uncertainties. Despite the offset, we show that the probability of finding an unrelated transient within 40 arcsec of the GRB location is |$\lt 10^{-6}$| and conclude that this is a candidate radio counterpart to GRB 201006A. We performed image plane dedispersion and the radio flash is tentatively (2.4 |$\sigma$|⁠) shown to be highly dispersed, allowing a distance estimate, corresponding to a redshift of |$0.58\pm 0.06$|⁠. The corresponding luminosity of the event at this distance is |$6.7^{+6.6}_{-4.4} \times 10^{32}$| erg s |$^{-1}$| Hz |$^{-1}$|⁠. If associated with GRB 201006A, this emission would indicate prolonged activity from the central engine that is consistent with being a newborn, supramassive, likely highly magnetized, millisecond spin neutron star (a magnetar). [ABSTRACT FROM AUTHOR]

The objective of this paper is to deal with physical features of charged anisotropic compact objects in the framework of f(R,ϕ,X) modified theory of gravity. To accomplish the desired objective, we consider a spherically symmetric spacetime with charged anisotropic fluid distribution. In addition, we utilize the Krori–Barua metric, i.e. λ(r)=Xr2 + Y and β(r) = Zr2 for exploring the field equations. Moreover, we compare the interior boundary to the bardeen model as an exterior geometry to calculate the unknown constrains. Further, to check the existence of bardeen stellar structure, we discuss the behavior of physical properties such as energy density, pressure components, anisotropy, equation of state parameters, stability analysis, energy bounds, equilibrium condition, adiabatic index, compactness factor and surface redshift. Conclusively, all the obtained results show that the system under consideration is physically stable, free from singularity and viable. [ABSTRACT FROM AUTHOR]

The mass assembly history (MAH) of dark matter haloes plays a crucial role in shaping the formation and evolution of galaxies. MAHs are used extensively in semi-analytic and empirical models of galaxy formation, yet current analytic methods to generate them are inaccurate and unable to capture their relationship with the halo internal structure and large-scale environment. This paper introduces florah (FLOw-based Recurrent model for Assembly Histories), a machine-learning framework for generating assembly histories of ensembles of dark matter haloes. We train florah on the assembly histories from the Gadget at Ultra-high Redshift with Extra Fine Time-steps and vsmdpl N -body simulations and demonstrate its ability to recover key properties such as the time evolution of mass and concentration. We obtain similar results for the galaxy stellar mass versus halo mass relation and its residuals when we run the Santa Cruz semi-analytic model on florah -generated assembly histories and halo formation histories extracted from an N -body simulation. We further show that florah also reproduces the dependence of clustering on properties other than mass (assembly bias), which is not captured by other analytic methods. By combining multiple networks trained on a suite of simulations with different redshift ranges and mass resolutions, we are able to construct accurate main progenitor branches with a wide dynamic mass range from |$z=0$| up to an ultra-high redshift |$z \approx 20$|⁠ , currently far beyond that of a single N -body simulation. florah is the first step towards a machine learning-based framework for planting full merger trees; this will enable the exploration of different galaxy formation scenarios with great computational efficiency at unprecedented accuracy. [ABSTRACT FROM AUTHOR]

Understanding physical mechanisms relies on the accurate determination of fundamental constants, although inherent limitations in experimental techniques introduce uncertainties into these measurements. This paper explores the uncertainties associated with measuring the fine-structure constant (⁠|$\alpha$|⁠) and the proton-to-electron mass ratio (⁠|$\mu$|⁠) using observed fast radio bursts (FRBs). We select 50 localized FRBs to quantify the effects of varying this fundamental coupling on the relation between dispersion measure and redshift. By leveraging independent measurements of dispersion measures and redshifts of these FRBs, we constrain the uncertainties in |$\alpha$| and |$\mu$| approximately to |$\Delta \alpha /\alpha =1.99\times 10^{-5}$| and |$\Delta \mu /\mu =-1.00\times 10^{-5}$| within the standard |$\Lambda$| CDM cosmological framework. Remarkably, these constraints improve nearly an order-of-magnitude when considering a dynamical dark energy model. This investigation not only yields one of the most stringent constraints on |$\alpha$| and |$\mu$| to date but also emphasizes the criticality of accounting for the energy scale of the system when formulating constraints on fundamental parameters. [ABSTRACT FROM AUTHOR]

In this paper, a highly sensitive fiber-optic sensor was proposed for the detection of Cu2+ traces in aqueous solution which has a nonnegligible impact on human health. Based on the principle of SPR, a uniform chitosan (CS) material was coated on a multimode fiber-single mode fiber-multimode fiber (MSM) structure with silver layer by glutaraldehyde (GLA) and graphene oxide modification. The amino and hydroxyl groups in the material have a recognition function for Cu2+, which can chelate with Cu2+ and change the ambient layer refractive index of the sensor leading to a shift in the SPR spectrum. Trace Cu2+ can be detected by monitoring the shift in the resonance wavelength of the SPR spectrum. The results illustrate that within the range of 0.1 ~ 1 mg/L Cu2+ concentration, as the Cu2+ concentration increasing, the SPR spectrum undergoes a red shift and the maximum detection sensitivity of Cu2+ ions achieves 49.466 nm/(mg/L), with a good linearity of 0.996. The temperature experimental results indicate that the sensor has good stability at room temperature (25 ~ 35 °C). The stability and repeatability characteristics of the system are also investigated. The good performance provides a new method in trace Cu2+ in-situ detection. [ABSTRACT FROM AUTHOR]

In this paper, the reconstructed growth index γ (z) is updated by jointed combination from Pantheon+ SNe Ia samples, the observed Hubble data points H (z) at the background level, and redshift space distortion measurements of f σ 8 (z) at the linear perturbation level via Gaussian process. The reconstructed results show that the currently available data points suggest a mild time varying growth index at low redshifts within 3 σ regions. No significant deviation from ΛCDM cosmology in GR within 3 σ regions was found, while the growth indices for the f (R) and the Dvali–Gabadadze–Porrati gravity are at the boundaries of 3 σ regions. [ABSTRACT FROM AUTHOR]

The unimodular theory of gravity is an alternative perspective to the traditional general relativity of Einstein and opens new possibilities for exploring its implications in cosmology. In this paper, we investigated Unimodular Gravity (UG) with the cosmological data from the Pantheon sample of Type Ia Supernovae (SNs) (2018), Baryon Acoustic Oscillations (BAOs), and the observational H(z) data from the Differential Age method (DA). We also used the Cosmic Microwave Background (CMB) distance priors from the Planck 2018 results. We considered a model consisting of a generalized cosmological constant, radiation, and a dark matter component along with normal matter. The considered theory respects only unimodular coordinate transformations. We first fit our model with low-redshift data from SNs and DA and determined the value of the model parameters (ξ , H 0) . We found the best-fit value of parameter ξ = 6.03 ± 0.40 , which deviates slightly from 6, for which the theory becomes the standard general theory of relativity. We observed a small deviation in the value of the Hubble constant ( H 0 = 72.6 ± 3.5 km s−1 Mpc−1) in the UG model compared with the standard Λ CDM model ( H 0 = 72.2 ± 1.2 km s−1 Mpc−1). Using the BAO + CMB constraint in the UG model, we obtained H 0 = 68.45 ± 0.66 km s − 1 Mpc − 1 , and ξ is ∼6.029. For the combined datasets (SN + DA + BAO + CMB), the estimated H 0 = 69.01 ± 0.60 km s − 1 Mpc − 1 with ξ ∼ 6.037, and in standard gravity, H 0 = 68.25 ± 0.40 km s − 1 Mpc − 1 . [ABSTRACT FROM AUTHOR]

In this paper, using the latest Pantheon+ sample of Type Ia supernovae, baryon acoustic oscillation measurements, and observational Hubble data, we carry out a joint constraint on the Hubble constant H 0, the spatial curvature ΩK, and the sound horizon at the end of the drag epoch r d. To be model-independent, four cosmography models—i.e., the Taylor series in terms of redshift y 1 = z /(1 + z), y 2 = arctan (z) , y 3 = ln (1 + z) , and the Padé approximants—are used without the assumption of a flat Universe. The results show that H 0 is anticorrelated with ΩK and r d, indicating that smaller ΩK or r d would be helpful in alleviating the Hubble tension. The values of H 0 and r d are consistent with the estimate derived from the Planck cosmic microwave background data based on the flat ΛCDM model, but H 0 is in 2.3 ∼ 3.0 σ tension with that obtained by Riess et al. in all these cosmographic approaches. Meanwhile, a flat Universe is preferred by the present observations under all approximations except the third order of y 1 and y 2 of the Taylor series. Furthermore, according to the values of the Bayesian evidence, we found that the flat ΛCDM remains to be the most favored model by the joint data sets, and the Padé approximant of order (2,2), the third order of y 3 and y 1 are the top three cosmographic expansions that fit the data sets best, while the Taylor series in terms of y 2 are essentially ruled out. [ABSTRACT FROM AUTHOR]

Measurements of the validity of General Relativity, as well as its effects in quantum mechanics, are becoming increasingly accessible to tabletop experiments. In this paper, we will introduce atomic clocks and explain the pathway to observing state-of-the-art gravitational redshift using atomic clocks, with the help of existing experimental examples. We will conclude with possible future directions. [ABSTRACT FROM AUTHOR]

This paper proposes a new framework to investigate the spherically symmetric of anisotropic stars with clouds of strings and quintessence field in Rastall gravity. We develop the field equations in a spherically symmetric space–time with a quintessence field and clouds of string. We utilize the mass and radius of Her X-1, Vela X-1, SMC X-1, SAX J1808 0.4-3658 and 4 U 1538-52, which are well mentioned in the literature. We applied the matching conditions by considering outer space calculated in Rastall gravity to evaluate the constants parameters. To check the stability and physical presence of compact models, we computed the most important features of quintessence stars in the presence of a cloud of strings. We explored characteristics including energy density, quintessence density, radial pressure, tangential pressure gradients, anisotropic factor, energy conditions, sound speeds, TOV forces, EoS components, mass function, compactification and redshift. [ABSTRACT FROM AUTHOR]

This paper examines the structure of a gravitational vacuum star (also known as gravastar) in the background of f (ℜ , 2) theory. This hypothetical object can be treated as a substitute of a black hole, with three regions: (i) the internal region, (ii) the intrinsic shell and (iii) the outer region. We examine these geometries using Finch–Skea metric for the radial metric component along with the particular f (ℜ , 2) model. We determine singularity-free solutions for both the inner as well as thin-shell domains. The smooth matching of the interior region with external Schwarzschild spacetime is obtained through Israel matching constraints. Finally, we study various characteristics of gravastar domains including the equation-of-state parameter, proper length, entropy, energy as well as surface redshift. It is found that the compact gravastar structure is a viable alternate to the black hole in the perspective of this gravity. [ABSTRACT FROM AUTHOR]

In this paper, an attempt is made to construct a Friedmann–Lemaitre–Robertson–Walker model in f (R , T) gravity with a perfect fluid that yields acceleration at late times. We take f (R , T) as R + 8 π μ T. As in the Λ CDM model, we take the matter to consist of two components, viz., Ω m and Ω μ such that Ω m + Ω μ = 1. The parameter Ω m is the matter density (baryons + dark matter), and Ω μ is the density associated with the Ricci scalar R and the trace T of the energy–momentum tensor, which we shall call dominant matter. We find that at present Ω μ is dominant over Ω m , and that the two are in the ratio 3:1–3:2 according to the three data sets: (i) 77 Hubble OHD data set, (ii) 580 SNIa supernova distance modulus data set and (iii) 66 pantheon SNIa data which include high red shift data in the range 0 ≤ z ≤ 2. 3 6. We have also calculated the pressures and densities associated with the two matter densities, viz., p μ , ρ μ , p m and ρ m , respectively. It is also found that at present, ρ μ is greater than ρ m . The negative dominant matter pressure p μ creates acceleration in the universe. Our deceleration and snap parameters show a change from negative to positive, whereas the jerk parameter is always positive. This means that the universe is at present accelerating and in the past it was decelerating. State finder diagnostics indicate that our model is at present a dark energy quintessence model. The various other physical and geometric properties of the model are also discussed. [ABSTRACT FROM AUTHOR]

The Hubble tension has now grown to a level of significance which can no longer be ignored and calls for a solution which, despite a huge number of attempts, has so far eluded us. Significant efforts in the literature have focused on early-time modifications of Λ CDM, introducing new physics operating prior to recombination and reducing the sound horizon. In this opinion paper I argue that early-time new physics alone will always fall short of fully solving the Hubble tension. I base my arguments on seven independent hints, related to (1) the ages of the oldest astrophysical objects, (2) considerations on the sound horizon-Hubble constant degeneracy directions in cosmological data, (3) the important role of cosmic chronometers, (4) a number of "descending trends" observed in a wide variety of low-redshift datasets, (5) the early integrated Sachs-Wolfe effect as an early-time consistency test of Λ CDM, (6) early-Universe physics insensitive and uncalibrated cosmic standard constraints on the matter density, and finally (7) equality wavenumber-based constraints on the Hubble constant from galaxy power spectrum measurements. I argue that a promising way forward should ultimately involve a combination of early- and late-time (but non-local—in a cosmological sense, i.e., at high redshift) new physics, as well as local (i.e., at z ∼ 0 ) new physics, and I conclude by providing reflections with regards to potentially interesting models which may also help with the S 8 tension. [ABSTRACT FROM AUTHOR]

The paper considers significant cosmological events that occurred in 2007: the reason for discrepancies in Hubble constant estimates was established; the galactic polar redshift anisotropy within the spectra of extragalactic sources was indicated; a cold spot of cosmic microwave background was detected; the so-called extraordinary evidence of the accelerated expansion of the universe was obtained. This evidence is based on analyzing data on Type Ia supernovae belonging to the Hubble Deep and Ultra Deep Fields. A chain of results is described that led to an alternative hypothesis — acceleration of large-scale galactic flows under the action of the gravitational dipoles of large-scale inhomogeneity of the universe in the form of "giant void–massive supercluster" pairs on opposite sides of the celestial sphere. The author presents the results of testing (for inadequacy) the Friedmann–Robertson–Walker isotropic model of the calibration function of the cosmological redshift distance scale adopted in this extraordinary evidence. It is shown that structural changes and rank inversions of the isotropic model are interpreted as the action of gravitational dipoles due to the existence of a more accurate anisotropic model of the calibration function of the cosmological redshift distance scale. This hypothesis is an alternative to that about the accelerated expansion of the universe. It is shown that the Hubble Deep and Ultra Deep Fields are a gravitational dipole — Hubble dipole. [ABSTRACT FROM AUTHOR]

In this paper, for the first time, we report a strong effect of the arsenic pressure used for the high-rate GaAs capping of self-assembled InAs quantum dots on their optical properties. A 140 nm red shift of the photoluminescence peak position is observed when the overgrowth arsenic pressure increases threefold. We explain this behavior in terms of different intensities of quantum dot decomposition, which occurs during the overgrowth under different conditions. When the arsenic pressure is sufficiently high, a GaAs capping layer is formed by deposited species with a low impact on initial quantum dots. At a low arsenic pressure, arsenic deficiency leads to the intensive intermixing caused both by the enhanced Ga/In atom exchange and by the consumption of arsenic atoms belonging to quantum dots for the GaAs capping layer formation. As a result of the overgrowth, quantum dots are divided into families with a large (high pressure) and a small (low pressure) average size, yielding long-wave (1.23 µm) and short-wave (1.09 µm) photoluminescence peaks, respectively. Thus, a significant influence of the overgrowth arsenic pressure on the characteristics of InAs quantum dots is evidenced in this study. [ABSTRACT FROM AUTHOR]

Recent observations indicate that the Universe is not transparent but partially opaque due to absorption of light by ambient cosmic dust. This implies that the Friedmann equations valid for the transparent universe must be modified for the opaque universe. This paper studies a scenario in which the opacity rises with redshift. In this case, the light–matter interactions become important, because cosmic opacity produces radiation pressure that counterbalances gravitational forces. The presented theoretical model assumes the Universe is expanding according to the standard FLRW metric but with the scale factor a(t) depending on both types of forces: gravity as well as radiation pressure. The modified Friedmann equations predict a cyclic expansion/contraction evolution of the Universe within a limited range of scale factors with no initial singularity. The model avoids dark energy and removes some other tensions of the standard cosmological model. The paper demonstrates that considering light–matter interactions in cosmic dynamics is crucial and can lead to new cosmological models essentially different from the standard Λ CDM model. This emphasizes the necessity of new observations and studies of cosmic opacity and cosmic dust at high redshifts for more realistic modelling of the evolution of the Universe. [ABSTRACT FROM AUTHOR]

Several hundred gamma-ray burst (GRB) redshifts have been determined to date. One of the other important properties—besides the distance—of the GRBs is the duration of the burst. In this paper, we analyse these two important quantities of the phenomena. In this paper, we map the two-dimensional distribution and explore some suspicious areas. As it is well known that the short GRBs are closer than the others, we search for parts in the Universe where the GRB duration is different from the others. We also analyse whether there are any ranges in the duration where the redshifts differ. We find some suspicious areas, however, no other significant region was found than the short GRB region. [ABSTRACT FROM AUTHOR]

This paper shows that gravitational results of general relativity (GR) can be reached by using special relativity (SR) via a SR Lagrangian that derives from the corresponding GR time dilation and vice versa. It also presents a new SR gravitational central scalar generalized potential V = V (r , r. , ϕ.) , where r is the distance from the center of gravity and r. , ϕ. are the radial and angular velocity, respectively. This is associated with the Schwarzschild GR time dilation from where a SR scalar generalized potential is obtained, which is exactly equivalent to the Schwarzschild metric. Thus, the Precession of Mercury's Perihelion, the Gravitational Deflection of Light, the Shapiro time delay, the Gravitational Red Shift, etc., are explained with the use of SR only. The techniques used in this paper can be applied to any GR spacetime metric, Teleparallel Gravity, etc., in order to obtain the corresponding SR gravitational scalar generalized potential and vice versa. Thus, the case study of Newtonian Gravitational Potential according to SR leads to the corresponding non-Riemannian metric of GR. Finally, it is shown that the mainstream consideration of the Gravitational Red Shift contains two approximations, which are valid in weak gravitational fields only. [ABSTRACT FROM AUTHOR]

Pulse coherence and spatial beam quality are important physical parameters to evaluate the quality of ultrafast lasers. In this paper, spatiotemporal deterioration (STD) of multidimensional light field is proposed to depict the degradation of coherence in both temporal and spatial domains in nonlinear ultrafast fiber amplifiers. Simulation results uncover that in gain-managed nonlinearity (GMN) pulse amplifiers, once the STD threshold is reached, beam quality quickly degrades, Raman noise intensifies, pulsed coherence decreases, and pulse compression becomes challenging. The findings demonstrate that stimulated Raman scattering is the primary cause of STD, which triggers a rapid energy transfer of the blue-wavelength portion of fundamental mode to higher-order modes when phase matching is satisfied by the strong Kerr effect in the GMN regime. Moreover, gain redshift that dominates the redshift of the pulse spectrum can considerably drive the energy transfer and, hence, accelerates STD in the nonlinear regime, while suppressing STD in the linear regime. Finally, the effects of seed characteristics and pump wavelength on STD are also studied, and methods to suppress STD in GMN amplifiers are presented. These findings we believe can provide insight into high-energy ultrafast fiber amplifiers for generating high-coherent, high-beam-quality, sub-50 fs, and μJ level pulses at 1 μm and other complex multimode gain systems. [ABSTRACT FROM AUTHOR]

One of the most important issues in cosmology is the study of a series of hypothetical objects called wormholes. Recently, researchers have studied these hypothetical objects under different conditions. In this paper, we aim to evaluate the traversable wormhole according to a modified f (R) gravitational model, specifically − R 2 + a R 2 (1 − n) , from the perspective of two essential functions in wormhole structure: shape and redshift function. These hypothetical objects can solve Einstein's equations by tolerating the violation of null energy conditions (NEC). With respect to these concepts, we examine various energy conditions such as the NEC, weak energy condition (WEC), dominant energy condition (DEC) and strong energy condition (SEC) using radial pressure, tangential pressure and energy density obtained from the wormhole equations. Finally, we evaluate different energy conditions by plotting some figures and checking for satisfaction or violation. We will analyze the results and present the conclusions in tables. [ABSTRACT FROM AUTHOR]

This paper reports on the structural, optical and luminescence studies of Dy3+–Eu3+ co-doped glass ceramics that are obtained via thermal treatment method. The initial confirmation on glass ceramics with the formation of NaBSiO4 crystalline phase was made through XRD study. The FTIR study showed the vibrations of network formers (B2O3, SiO2) and other functional groups. The quantity of non-bridging oxygens (NBOs) are increased in the glass ceramics with increase in annealing temperature. The absorption spectra (UV–visible-NIR) showed the possible transitions of Dy3+ and Eu3+ ions in the glass ceramics. A red-shift in the absorption band-edge and reduction in the optical band gap values were obtained for glass ceramics owing to their heating temperatures. Photoluminescence studies showed the excitations of Dy3+ and Eu3+ ions under 575 nm and 613 nm emission wavelengths. The obtained NaBSiO4 crystalline phase in the glass ceramics has enhanced the luminescence intensity, and lifetimes of Dy3+ and Eu3+ ions compared to unheated precursor glass when excited under 350 nm and 393 nm. Color chromaticity diagram and correlated color temperature (CCT) values showed a shift in the color of light from warm white of precursor glass to neutral white of glass ceramics. The overall results justify the possibility of considering the Dy3+-Eu3+ co-doped glass ceramics as efficient materials for solid-state lighting applications like W-LEDs. [ABSTRACT FROM AUTHOR]