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Statistical and computational methods are widely used in today's scientific studies. Using a female fertility potential in childhood cancer survivors as an example, we illustrate how these methods can be used to extract insight regarding biological processes from noisy observational data in order to inform decision making. We start by contextualizing the computational methods with the working example: the modelling of acute ovarian failure risk in female childhood cancer survivors to quantify the risk of permanent ovarian failure due to exposure to lifesaving but nonetheless toxic cancer treatments. This is followed by a description of the general framework of classification problems. We provide an overview of the modelling algorithms employed in our example, including one classic model (logistic regression) and two popular modern learning methods (random forest and support vector machines). Using the working example, we show the general steps of data preparation for modelling, variable selection steps for the classic model, and how model performance might be improved utilizing visualization tools. We end with a note on the importance of model evaluation., Comment: 15 pages, 9 figures and 1 table

We present a statistical analysis for the characteristics and radial evolution of linear magnetic holes (LMHs) in the solar wind from 0.166 to 0.82 AU using Parker Solar Probe observations of the first two orbits. It is found that the LMHs mainly have a duration less than 25 s and the depth is in the range from 0.25 to 0.7. The durations slightly increase and the depths become slightly deeper with the increasing heliocentric distance. Both the plasma temperature and the density for about 50% of all events inside the holes are higher than the ones surrounding the holes. The average occurrence rate is 8.7 events/day, much higher than that of the previous observations. The occurrence rate of the LMHs has no clear variation with the heliocentric distance (only a slight decreasing trend with the increasing heliocentric distance), and has several enhancements around ~0.525 AU and ~0.775 AU, implying that there may be new locally generated LMHs. All events are segmented into three parts (i.e., 0.27, 0.49 and 0.71 AU) to investigate the geometry evolution of the linear magnetic holes. The results show that the geometry of LMHs are prolonged both across and along the magnetic field direction from the Sun to the Earth, while the scales across the field extend a little faster than along the field. The present study could help us to understand the evolution and formation mechanism of the LMHs in the solar wind., Comment: Accepted by ApJ

The extremely neutron-rich system $^{7}$H was studied in the direct $^2$H($^8$He,$^3$He)$^7$H transfer reaction with a 26 AMeV secondary $^{8}$He beam [Bezbakh et al., Phys. Rev. Lett. 124 (2020) 022502]. The missing mass spectrum and center-of-mass (c.m.) angular distributions of $^{7}$H, as well as the momentum distribution of the $^{3}$H fragment in the $^{7}$H frame, were constructed. In addition to the investigation reported in Ref. [Bezbakh et al., Phys. Rev. Lett. 124 (2020) 022502], we carried out another experiment with the same beam but a modified setup, which was cross-checked by the study of the $^2$H($^{10}$Be,$^3$He$)^{9}$Li reaction. A solid experimental evidence is provided that two resonant states of $^{7}$H are located in its spectrum at 2.2(5) and 5.5(3) MeV relative to the $^3$H+4$n$ decay threshold. Also, there are indications that the resonant states at 7.5(3) and 11.0(3) MeV are present in the measured $^{7}$H spectrum. Based on the energy and angular distributions, obtained for the studied $^2$H($^8$He,$^3$He)$^7$H reaction, the weakly populated 2.2(5) MeV peak is ascribed to the $^7$H ground state. It is highly plausible that the firmly ascertained 5.5(3) MeV state is the $5/2^+$ member of the $^7$H excitation $5/2^+$-$3/2^+$ doublet, built on the $2^+$ configuration of valence neutrons. The supposed 7.5 MeV state can be another member of this doublet, which could not be resolved in Ref. [Bezbakh et al., Phys. Rev. Lett. 124 (2020) 022502]. Consequently, the two doublet members appeared in the spectrum of $^{7}$H in [Bezbakh et al., Phys. Rev. Lett. 124 (2020) 022502] as a single broad 6.5 MeV peak., Comment: 16 pages, 15 figures

Deep reinforcement learning is an emerging machine learning approach which can teach a computer to learn from their actions and rewards similar to the way humans learn from experience. It offers many advantages in automating decision processes to navigate large parameter spaces. This paper proposes a novel approach to the efficient measurement of quantum devices based on deep reinforcement learning. We focus on double quantum dot devices, demonstrating the fully automatic identification of specific transport features called bias triangles. Measurements targeting these features are difficult to automate, since bias triangles are found in otherwise featureless regions of the parameter space. Our algorithm identifies bias triangles in a mean time of less than 30 minutes, and sometimes as little as 1 minute. This approach, based on dueling deep Q-networks, can be adapted to a broad range of devices and target transport features. This is a crucial demonstration of the utility of deep reinforcement learning for decision making in the measurement and operation of quantum devices.

As the largest radio telescope in the world, the Square Kilometre Array (SKA) will lead the next generation of radio astronomy. The feats of engineering required to construct the telescope array will be matched only by the techniques developed to exploit the rich scientific value of the data. To drive forward the development of efficient and accurate analysis methods, we are designing a series of data challenges that will provide the scientific community with high-quality datasets for testing and evaluating new techniques. In this paper we present a description and results from the first such Science Data Challenge (SDC1). Based on SKA MID continuum simulated observations and covering three frequencies (560 MHz, 1400MHz and 9200 MHz) at three depths (8 h, 100 h and 1000 h), SDC1 asked participants to apply source detection, characterization and classification methods to simulated data. The challenge opened in November 2018, with nine teams submitting results by the deadline of April 2019. In this work we analyse the results for 8 of those teams, showcasing the variety of approaches that can be successfully used to find, characterise and classify sources in a deep, crowded field. The results also demonstrate the importance of building domain knowledge and expertise on this kind of analysis to obtain the best performance. As high-resolution observations begin revealing the true complexity of the sky, one of the outstanding challenges emerging from this analysis is the ability to deal with highly resolved and complex sources as effectively as the unresolved source population., Comment: 18 pages, 11 figures, accepted by MNRAS

Within the three-flavor PNJL and EPNJL chiral quark models we have obtained pseudoscalar meson properties in quark matter at finite temperature $T$ and baryochemical potential $\mu_B$. We compare the meson pole (Breit-Wigner) approximation with the Beth-Uhlenbeck (BU) approach that takes into account the continuum of quark-antiquark scattering states when determining the partial densities of pions and kaons. We evaluate the kaon-to-pion ratios along the (pseudo-)critical line in the $T-\mu_B$ plane as a proxy for the chemical freezeout line, whereby the variable $x=T/\mu_B$ is introduced that corresponds to the conserved entropy per baryon as initial condition for the heavy-ion collision experiments. We present a comparison with the experimental pattern of kaon-to-pion ratios within the BU approach and using $x$-dependent pion and strange quark potentials. A sharp "horn" effect in the energy dependence $K^+/\pi^+$ ratio is explained by the enhanced pion production at energies above $\sqrt{s_{NN}}=8$ GeV, when the system enters the regime of meson dominance. This effect is in line with the enhancement of low-momentum pion spectra that is discussed as a precursor of the pion Bose condensation and entails the occurrence of a nonequilibrium pion chemical potential of the order of the pion mass. We elucidate that the horn effect is not related to the existence of a critical endpoint in the QCD phase diagram., Comment: 20 pages, 7 figures

In the present article we have investigated a very natural question regarding the dynamics of the universe, namely, the possibility of its decelerating phase immediately after the present accelerating phase. To begin with, we have focused on the matter creation theory which is considered to be a viable alternative to dark energy and modified gravity models. Moreover, we have introduced the cosmographic approach which allows us to express the free parameters of a cosmological model in terms of the known cosmographic parameters. Assuming a generalized matter creation rate we have discussed the theoretical bounds on the model parameters allowing the future deceleration of the universe. Moreover, using the observational bounds on the cosmographic parameters obtained from the low redshifts observational probes, we have also examined the chance of a decelerating phase of the universe. Finally, considering a variety of known cosmological models and parametrizations, we have tested the same possibility. Our analysis shows that the chance of a future decelerating expansion of the universe is highly dependent on the choice of the cosmological models and parametrizations and also on the observational data. Even though the future decelerating expansion is allowed in some cosmological frameworks, but we do not see any strong evidence in favor of this. Perhaps, the future cosmological surveys could offer some more information regarding the fate of the universe., Comment: 18 pages, 1 Table and 5 Figures; typos corrected; version published in IJMPD

The method of asymptotic normalization coefficients is a standard approach for studies of two-body non-resonant radiative capture processes in nuclear astrophysics. This method suggests a fully analytical description of the radiative capture cross section in the low-energy region of the astrophysical interest. We demonstrate how this method can be generalized to the case of three-body $2p$ radiative captures. It was found that an essential feature of this process is the highly correlated nature of the capture. This reflects the complexity of three-body Coulomb continuum problem. Radiative capture $^{15}$O+$p$+$p \rightarrow ^{\,17}$Ne+$\gamma$ is considered as an illustration., Comment: 9 pages, 8 figures

We investigate how the direction of polarized light can affect the dichroism pattern seen in angle-resolved photoemission spectroscopy. To this end, we prepared a sample composed of highly-oriented Bi(111) micro-crystals that macroscopically has infinite rotational and mirror symmetry of the point group $\rm{C}_{\infty\rm{v}}$ and examined whether the dichroism pattern retains the $\rm{C}_{\infty\rm{v}}$ symmetry under the stationary configuration of the light and sample. The direction of the light was imprinted in the pattern. Thereby, we apply group theory and classify the pattern with the configuration of light taken into account. We complete the classification by discussing the cases when the out-of-plane component of the polarization can be neglected, when the incidence angle is either 0$^{\circ}$ or 90$^{\circ}$, when the polarization is either elliptic or linear, and also when the sample is a crystal.

The nature of the plasma wave modes around the ion kinetic scales in highly Alfv\'enic slow solar wind turbulence is investigated using data from the NASA's Parker Solar Probe taken in the inner heliosphere, at 0.18 Astronomical Unit (AU) from the sun. The joint distribution of the normalized reduced magnetic helicity ${\sigma}_m ({\theta}_{RB}, {\tau})$ is obtained, where ${\theta}_{RB}$ is the angle between the local mean magnetic field and the radial direction and ${\tau}$ is the temporal scale. Two populations around ion scales are identified: the first population has ${\sigma}_m ({\theta}_{RB}, {\tau}) < 0$ for frequencies (in the spacecraft frame) ranging from 2.1 to 26 Hz for $60^{\circ} < {\theta}_{RB} < 130^{\circ}$, corresponding to kinetic Alfv\'en waves (KAWs), and the second population has ${\sigma}_m ({\theta}_{RB}, {\tau}) > 0$ in the frequency range [1.4, 4.9] Hz for ${\theta}_{RB} > 150^{\circ}$, corresponding to Alfv\'en ion Cyclotron Waves (ACWs). This demonstrates for the first time the co-existence of KAWs and ACWs in the slow solar wind in the inner heliosphere, which contrasts with previous observations in the slow solar wind at 1 AU. This discrepancy between 0.18 and 1 AU could be explained, either by i) a dissipation of ACWs via cyclotron resonance during their outward journey, or by ii) the high Alfv\'enicity of the slow solar wind at 0.18 AU that may be favorable for the excitation of ACWs.

The traditional formulation of the ultimate goal of physics (in the narrower sense of axiomatic theory) involves the derivation of physical laws from first principles. Though, such option doesn't make things easier since the task of the first principles finding is not less complicated versus to the original problem. The alternative path for understanding the world around us is to interpret the fundamental limit values as a factor determining the physical laws structure. A significant part of this path has already been completed. It was possible to show that the quantum mechanics can be built on the basis of the existence of the minimum quantum action, while the special theory of relativity - on the maximum speed c. Furthermore, from rather recently it became clear that a similar approach could be implemented in general relativity but in this case it can be constructed by postulating the existence of a minimum lengths. The goal of this review is to demonstrate the effectiveness of limit values as a tool for describing the physics of the Planck scale. Moreover, by virtue of their universality, the limit values allow us to establish relationships between, on first glance, distant fields of physics. We will consider the simplest consequences of the inclusion of gravitational effects in quantum reality. The most important consequence of this consideration is the inevitability of transition from the classical concept of continuum to the concept of the discrete space-time. The new physics generated by such transition will be in the center of our attention., Comment: 45 pages, 7 figures

We consider a series of optimal control problems with 2-dimensional control lying in an arbitrary convex compact set $\Omega$. The considered problems are well studied for the case when $\Omega$ is a unit disc, but barely studied for arbitrary $\Omega$. We derive extremals to these problems in general case by using machinery of convex trigonometry, which allows us to do this identically and independently on the shape of $\Omega$. The paper describes geodesics in (i) the Finsler problem on the Lobachevsky hyperbolic plane; (ii) left-invariant sub-Finsler problems on all unimodular 3D Lie groups (SU(2), SL(2), SE(2), SH(2)); (iii) the problem of rolling ball on a plane with distance function given by $\Omega$; (iv) a series of "yacht problems" generalizing Euler's elastic problem, Markov-Dubins problem, Reeds-Shepp problem and a new sub-Riemannian problem on SE(2); and (v) the plane dynamic motion problem., Comment: 50 pages, 56 figures

We discuss recent progress in the development of the three-fluid hydrodynamics-based program THESEUS towards an event generator suitable for applications to heavy-ion collisions at the intermediate energies of the planned NICA and FAIR experiments. We follow the strategy that modifications of particle distributions at the freeze-out surface in the QCD phase diagram may be mapped directly to the observable ones within a sudden freeze-out scheme. We report first results of these investigations for the production of light clusters (deuterons and tritons) which can be compared to experimental data from the HADES and the NA49 experiment and for the interpretation of the "horn" effect observed in the collision energy dependence of the $K^+/\pi^+$ ratio. Medium effects on light cluster production in the QCD phase diagram are negligible at the highest NICA energies but shall play a dominant role at the lowest energies. A sharp "horn"-type signal in the $K^+/\pi^+$ ratio can be obtained when the onset of Bose condensation modelled by a pion chemical potential results in an enhancement of pions at low momenta (which is seen at LHC energies) and would occur already in the NICA energy range., Comment: 5 pages, 3 figures, 3 references added, contribution to the Proceedings of "III NICA Days-2019 and IV MPD Collaboration Meeting", Warsaw, 21.-25.10.2019

Quantum devices with a large number of gate electrodes allow for precise control of device parameters. This capability is hard to fully exploit due to the complex dependence of these parameters on applied gate voltages. We experimentally demonstrate an algorithm capable of fine-tuning several device parameters at once. The algorithm acquires a measurement and assigns it a score using a variational auto-encoder. Gate voltage settings are set to optimise this score in real-time in an unsupervised fashion. We report fine-tuning times of a double quantum dot device within approximately 40 min.

A sharp peak in the $K^+/\pi^+$ ratio in relativistic heavy-ion collision is discussed in the framework of the SU(3) Polyakov-loop extended NJL model with vector interaction. In the model, the $K^+/\pi^+$ ratio was calculated along the chiral phase transition line for different values of the vector coupling $g_V$. We showed that the value of the vector coupling had no significant effect on the $K^+/\pi^+$ behaviour., Comment: 6 pages, 3 figs

We show that in the SU(2)XU(1) spin-charge gauge approach we developed earlier one can attribute consistently an exclusion statistics with parameter 1/2 to the spinless charge carriers of the t-J model in two dimensions(2D), as it occurs in one dimension (1D). Like the 1D case, the no-double occupation constraint is at the origin of this fractional exclusion statistics. With this statistics we recover a "large" Fermi volume of holes at high dopings, close to that of the tight binding approximation. Furthermore, the composite nature of the hole, made of charge and spin carriers only weakly bounded, can provide a natural explanation of many unusual experimental features of the hole-doped cuprates.

The $^7$H system was populated in the $^2$H($^8$He,$^3$He)$^7$H reaction with a 26 AMeV $^8$He beam. The $^{7}$H missing mass energy spectrum, the $^{3}$H energy and angular distributions in the $^7$H decay frame were reconstructed. The $^7$H missing mass spectrum shows a peak which can be interpreted either as unresolved $5/2^+$ and $3/2^+$ doublet or one of these states at 6.5(5) MeV. The data also provide indications on the $1/2^+$ ground state of $^7$H located at 2.0(5) MeV with quite a low population cross section of $\sim 10$ $\mu$b/sr within angular range $\theta_{\text{cm}} \simeq 6^{\circ} - 30^{\circ}$.

Fine structure in the $\alpha$ decay of $^{223}$U was observed in the fusion-evaporation reaction $^{187}$Re($^{40}$Ar, p3n) by using fast digital pulse processing technique. Two $\alpha$-decay branches of $^{223}$U feeding the ground state and 244 keV excited state of $^{219}$Th were identified by establishing the decay chain $^{223}$U $\xrightarrow{\alpha_{1}}$ $^{219}$Th $\xrightarrow{\alpha_{2}}$ $^{215}$Ra $\xrightarrow{\alpha_{3}}$ $^{211}$Rn. The $\alpha$-particle energy for the ground-state to ground-state transition of $^{223}$U was determined to be 8993(17) keV, 213 keV higher than the previous value, the half-life was updated to be 62$^{+14}_{-10}$ $\mu$s. Evolution of nuclear structure for $N$ = 131 even-$Z$ isotones from Po to U was discussed in the frameworks of nuclear mass and reduced $\alpha$-decay width, a weakening octupole deformation in the ground state of $^{223}$U relative to its lighter isotones $^{219}$Ra and $^{221}$Th was suggested., Comment: 6 pages, 6 figures

The effect of model parameters in the equation of state for quark matter on the magnitude of the maximum mass of hybrid stars is examined. Quark matter is described in terms of the extended MIT bag model including corrections for one-gluon exchange. For nucleon matter in the range of densities corresponding to the phase transition, a relativistic equation of state is used that is calculated with two particle correlations taken into account based on using the Bonn meson-exchange potential. The Maxwell construction is used to calculate the characteristics of the first order phase transition and it is shown that for a fixed value of the strong interaction constant $\alpha_s$, the baryon concentrations of the coexisting phases grow monotonically as the bag constant B increases. It is shown that for a fixed value of the strong interaction constant $\alpha_s$, the maximum mass of a hybrid star increases as the bag constant $B$ decreases. For a given value of the bag parameter $B$, the maximum mass rises as the strong interaction constant $\alpha_s$ increases. It is shown that the configurations of hybrid stars with maximum masses equal to or exceeding the mass of the currently known most massive pulsar are possible for values of the strong interaction constant $\alpha_s>0.6$ and sufficiently low values of the bag constant., Comment: 9 pages, 3 figures

The integral parameters of neutron stars are studied taking into account the hadron-quark phase transition, which leads to the formation of a core of quark matter in the central part of a star. The quark matter is described using the local Nambu - Jona-Lasinio (NJL) model. The thermodynamic characteristics of the hadron matter are calculated in the framework of an extended version of the relativistic mean field (RMF) model that includes the contribution of the scalar-isovector $\delta$-meson effective field. A Maxwell construction is used to determine the parameters of the phase transition. It is shown that for the equation of state examined here, stable hybrid stars correspond to a narrow range of values for the central density. In our model hybrid stars lie on the same branch as neutron stars, so that a branch with a third family is not formed. It is shown that for the equation of state examined here, stable hybrid stars correspond to a narrow range of values for the central density $\rho_c\in(1.71 \div 1.73]\cdot 10^{15}$ g/cm$^3$. In our model hybrid stars lie on the same branch as neutron stars, so that a branch with a third family is not formed. The maximum mass of a stable hybrid star is found to be $M_{max} = 2.05 M_\odot$. The configuration with the maximum mass has a quark core with mass $M_{core} \approx 10^{-3} M_\odot$ and radius $R_{core} \approx 0.6$ km., Comment: 16 pages, 3 figures, 2 tables

We report the discovery of HATS-71b, a transiting gas giant planet on a P = 3.7955 day orbit around a G = 15.35 mag M3 dwarf star. HATS-71 is the coolest M dwarf star known to host a hot Jupiter. The loss of light during transits is 4.7%, more than any other confirmed transiting planet system. The planet was identified as a candidate by the ground-based HATSouth transit survey. It was confirmed using ground-based photometry, spectroscopy, and imaging, as well as space-based photometry from the NASA TESS mission (TIC 234523599). Combining all of these data, and utilizing Gaia DR2, we find that the planet has a radius of $1.080 \pm 0.016 R_J$ and mass of $0.45 \pm 0.24 M_J$ (95% confidence upper limit of $0.81 M_J$ ), while the star has a mass of $0.569 \pm^{0.042}_{0.069}\,M_\odot$ and a radius of $0.5161\pm^{0.0053}_{0.0099}\,R_\odot$. The Gaia DR2 data show that HATS-71 lies near the binary main sequence in the Hertzsprung-Russell diagram, suggesting that there may be an unresolved stellar binary companion. All of the available data is well fitted by a model in which there is a secondary star of mass $0.24 M_\odot$, although we caution that at present there is no direct spectroscopic or imaging evidence for such a companion. Even if there does exist such a stellar companion, the radius and mass of the planet would be only marginally different from the values we have calculated under the assumption that the star is single., Comment: Submitted to AJ

Based on the cosmological principle only, the method of describing the evolution of the Universe, called cosmography, is in fact a kinematics of cosmological expansion. The effectiveness of cosmography lies in the fact that it allows, based on the results of observations, to perform a rigid selection of models that do not contradict the cosmological principle. It is important that the introduction of new components (dark matter, dark energy or even more mysterious entities) will not affect the relationship between the kinematic characteristics (cosmographic parameters) This paper shows that within the framework of cosmography the parameters of any model that satisfies the cosmological principle (the universe is homogeneous and isotropic on large scale), can be expressed through cosmographic parameters. The proposed approach to finding the parameters of cosmological models has many advantages. Emphasize that all the obtained results are accurate, since they follow from identical transformations. The procedure can be generalized to the case of models with interaction between components., Comment: 66 pages, 4 figures