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Vitrimers are polymer networks that can undergo bond exchange reactions. They dynamically rearrange their structures while maintaining their overall integrity, thus resulting in unique properties such as self-healing, reprocessability, shape memory and adaptability. Here, we show that the introduction of dynamic bonds directly impacts the polymer density. For a limiting case, where the dynamic bonds are the same size as the polymer chain bonds, simulations and theory show an enhancement in the density, because these bonds induce an increased cohesive force in the liquid, which is entropic in origin. The crosslinks are well mixed in the bulk but are depleted from the air and polymer interface. These findings implicate density as a key variable in polymers with dynamic crosslinkers, one that can be used to facilely tune their properties.

Prediction of solubility has been a complex and challenging physiochemical problem that has tremendous implications in the chemical and pharmaceutical industry. Recent advancements in machine learning methods have provided great scope for predicting the reliable solubility of a large number of molecular systems. However, most of these methods rely on using physical properties obtained from experiments and or expensive quantum chemical calculations. Here, we developed a method that utilizes a graphical representation of solute-solvent interactions using `MolMerger', which captures the strongest polar interactions between molecules using Gasteiger charges and creates a graph incorporating the true nature of the system. Using these graphs as input, a neural network learns the correlation between the structural properties of a molecule in the form of node embedding and its physiochemical properties as output. This approach has been used to calculate molecular solubility by predicting the Log solubility values of various organic molecules and pharmaceuticals in diverse sets of solvents., Comment: 22 pages, 9 Figures

In the realm of two-dimensional (2D) systems, the renowned Mermin-Wagner effect plays a significant role, giving rise to striking dimensionality effects marked by far-reaching density fluctuations and the divergence of various dynamic properties. This effect also unequivocally negates the possibility of stable crystalline phases in 2D particulate systems characterized by continuous degrees of freedom. This effect has been recently discerned in glass-forming liquids, displaying characteristic signatures like the logarithmic divergence of mean squared displacement in the plateau regime. We explored these long-wavelength fluctuations in crystalline solids and in glass-forming liquids in the presence of non-equilibrium active forces. These systems are known in the literature as active crystals and glasses, and they can be thought of as a minimalistic model for understanding various non-equilibrium systems where the constituent particles dynamics are controlled by both temperature and other active forces, which can be external or internal. Such models often offer valuable insights into the dynamical behavior of biological systems, such as collections of cells, bacteria, ant colonies, or even synthetic self-propelled particles like Janus colloids. Our study reveals that fluctuations stemming from active forces get strongly coupled with long wavelength fluctuations arising from thermal effects, resulting in dramatic dynamical effects, particularly in 2D systems. We also shed light on how these fluctuations impact dynamical heterogeneity, a defining characteristic of glassy dynamics.

In 1998, Wang constructed an ergodic action of the compact quantum group $U_n^+$ (free unitary quantum group) on the Cuntz algebra $\mathcal{O}_n$. Later, in 2018-2019, S. Joardar and A. Mandal showed that the quantum automorphism group of the Cuntz algebra $\mathcal{O}_{n}$ (as a graph $C^*$-algebra) is $U_n^+$ in the category introduced by them. In this article, we explore the quantum symmetry of the direct sum of Cuntz algebras viewing them as a graph $C^*$-algebra in the category as mentioned before. It has been shown that the quantum automorphism group of the direct sum of non-isomorphic Cuntz algebras $\{\mathcal{O}_{n_i}\}_{i=1}^{m}$ is ${U}_{n_1}^{+}*{U}_{n_2}^{+}* \cdots *{U}_{n_m}^{+}$ for distinct $n_i$'s, i.e. if $ L_{n_i}$ (the graph contains $n_i$ loops based at a single vertex) is the underlying graph of $\mathcal{O}_{n_i}$, then \begin{equation*} Q_{\tau}^{Lin}(\sqcup_{i=1}^{m} ~ L_{n_i}) \cong *_{i=1}^{m} ~~ Q_{\tau}^{Lin}(L_{n_i}) \cong {U}_{n_1}^{+}*{U}_{n_2}^{+}* \cdots *{U}_{n_m}^{+}. \end{equation*} Moreover, the quantum symmetry of the direct sum of $m$ copies of isomorphic Cuntz algebra $\mathcal{O}_n$ (whose underlying graph is $L_n$) is $U_n^+ \wr_* S_m^+,$ i.e. \begin{equation*} Q_{\tau}^{Lin}(\sqcup_{i=1}^{m} ~ L_n) \cong Q_{\tau}^{Lin}(L_n) \wr_* S_m^+ \cong U_n^+ \wr_* S_m^+. \end{equation*} On the other hand, it is known that the quantum automorphism group of $m$ disjoint copies of a simple, connected graph $\Gamma$ is isomorphic to the free wreath product of the quantum automorphism group of $\Gamma$ with $S_m^+$. Though an analoguous result is true for $\mathcal{O}_{n}$ (as a graph $C^*$-algebra), we have provided a counter-example to show that this result is not in general true for an arbitrary graph $C^*$-algebra., Comment: A new remark has been added. Few stylistic changes have been done. Comments are welcome

A quandle equipped with a good involution is referred to as symmetric. It is known that the cohomology of symmetric quandles gives rise to strong cocycle invariants for classical and surface links, even when they are not necessarily oriented. In this paper, we introduce the category of symmetric quandle modules and prove that these modules completely determine the Beck modules in the category of symmetric quandles. Consequently, this establishes suitable coefficient objects for constructing appropriate (co)homology theories. We develop an extension theory of modules over symmetric quandles and propose a generalized (co)homology theory for symmetric quandles with coefficients in a homogeneous Beck module, which also recovers the symmetric quandle (co)homology developed by Kamada and Oshiro [Trans. Amer. Math. Soc. (2010)]. Our constructions also apply to symmetric racks. We conclude by establishing an explicit isomorphism between the second cohomology of a symmetric quandle and the first cohomology of its associated group., Comment: 30 pages

There is an evident lack of implementation of Machine Learning (ML) in the legal domain in India, and any research that does take place in this domain is usually based on data from the higher courts of law and works with English data. The lower courts and data from the different regional languages of India are often overlooked. In this paper, we deploy a Convolutional Neural Network (CNN) architecture on a corpus of Hindi legal documents. We perform a bail Prediction task with the help of a CNN model and achieve an overall accuracy of 93\% which is an improvement on the benchmark accuracy, set by Kapoor et al. (2022), albeit in data from 20 districts of the Indian state of Uttar Pradesh., Comment: Accepted on 20th International Conference on Natural Language Processing (ICON)

Post-quantum cryptographic (PQC) algorithms, especially those based on the learning with errors (LWE) problem, have been subjected to several physical attacks in the recent past. Although the attacks broadly belong to two classes - passive side-channel attacks and active fault attacks, the attack strategies vary significantly due to the inherent complexities of such algorithms. Exploring further attack surfaces is, therefore, an important step for eventually securing the deployment of these algorithms. Also, it is important to test the robustness of the already proposed countermeasures in this regard. In this work, we propose a new fault attack on side-channel secure masked implementation of LWE-based key-encapsulation mechanisms (KEMs) exploiting fault propagation. The attack typically originates due to an algorithmic modification widely used to enable masking, namely the Arithmetic-to-Boolean (A2B) conversion. We exploit the data dependency of the adder carry chain in A2B and extract sensitive information, albeit masking (of arbitrary order) being present. As a practical demonstration of the exploitability of this information leakage, we show key recovery attacks of Kyber, although the leakage also exists for other schemes like Saber. The attack on Kyber targets the decapsulation module and utilizes Belief Propagation (BP) for key recovery. To the best of our knowledge, it is the first attack exploiting an algorithmic component introduced to ease masking rather than only exploiting the randomness introduced by masking to obtain desired faults (as done by Delvaux). Finally, we performed both simulated and electromagnetic (EM) fault-based practical validation of the attack for an open-source first-order secure Kyber implementation running on an STM32 platform.

We undertake a numerical study of the ordering kinetics in the two-dimensional ($2d$) active Ising model (AIM), a discrete flocking model with a conserved density field coupled to a non-conserved magnetization field. We find that for a quench into the liquid-gas coexistence region and in the ordered liquid region, the characteristic length scale of both the density and magnetization domains follows the Lifshitz-Cahn-Allen (LCA) growth law: $R(t) \sim t^{1/2}$, consistent with the growth law of passive systems with scalar order parameter and non-conserved dynamics. The system morphology is analyzed with the two-point correlation function and its Fourier transform, the structure factor, which conforms to the well-known Porod's law, a manifestation of the coarsening of compact domains with smooth boundaries. We also find the domain growth exponent unaffected by different noise strengths and self-propulsion velocities of the active particles. However, transverse diffusion is found to play the most significant role in the growth kinetics of the AIM. We extract the same growth exponent by solving the hydrodynamic equations of the AIM.

The dynamics of dense particle packings near the jamming transition is characterized by correlated particle motion. The growth of dynamical heterogeneities, or strong spatial variations in the motion of the particles constituting the system, is a hallmark feature of slow glassy dynamics. We report here a systematic confocal microscopy study that characterizes the cooperative dynamics of fluorescently-labelled colloidal particles in dense aqueous suspensions. We demonstrate that jammed particulate suspensions can be fluidized by increasing the width of the particle size distribution. Our molecular dynamics simulations, performed to numerically investigate the effects of continuous-size polydispersity on dense particle packing dynamics, show an excellent match with our experimental results. Besides shedding light on the fundamental aspects of particle-scale dynamics at the jamming-unjamming transition, our findings are significant in the processing of commonly-encountered dense suspensions such as paints, cosmetics, and food.

Shapley values, originating in game theory and increasingly prominent in explainable AI, have been proposed to assess the contribution of facts in query answering over databases, along with other similar power indices such as Banzhaf values. In this work we adapt these Shapley-like scores to probabilistic settings, the objective being to compute their expected value. We show that the computations of expected Shapley values and of the expected values of Boolean functions are interreducible in polynomial time, thus obtaining the same tractability landscape. We investigate the specific tractable case where Boolean functions are represented as deterministic decomposable circuits, designing a polynomial-time algorithm for this setting. We present applications to probabilistic databases through database provenance, and an effective implementation of this algorithm within the ProvSQL system, which experimentally validates its feasibility over a standard benchmark., Comment: 27 pages, including 20 pages of maintext. This is the authors' version of the corresponding PODS'2024 article

Time-dependent gravitational background is well known as a theoretical laboratory for quantum mechanical particle production. In the present analysis, we explore such production in a time-dependent analog system. This is the follow-up of our earlier study on the Sonoluminescence phenomenon, which is modelled in terms of analog geometry coupled with the electromagnetic field exhibiting the quantum production of photons. In the same analog geometry, we studied fermion production. Although fermions have not been observed yet in the sonoluminescence experiment, we have shown here that such a system can produce a repeated flux of fermions via the parametric resonance from a quantum vacuum. Our analysis seems to suggest that in the laboratory setup, time-dependent analog systems could be an interesting playground where phenomena of quantum mechanical particle production can be observed., Comment: Published version

We present an X-ray and UV investigation of five X-ray flares detected on two active systems, CC Eri and AB Dor, using the AstroSat observatory. The peak X-ray luminosities of the flares in the 0.3$-$7.0 keV band are found to be within 10$^{31-33}$ erg s$^{-1}$. Preliminary spectral analysis indicates the presence of three and four-temperature corona for CC Eri and AB Dor, respectively, where the highest temperature is found to vary with flare. The flare temperatures peaked at 51$-$59 MK for CC Eri and 29$-$44 MK for AB Dor. The peak emission measures of the flaring loops are estimated to be $\sim$10$^{54}$ for CC Eri and $\sim$10$^{55}$ cm$^{-3}$ for AB Dor. Global metallic abundances were also found to increase during flares., Comment: 8 pages, 3 figures, Accepted for publication in Bulletin de la Soci\'et\'e Royale des Sciences de Li\`ege (BSRSL)

Late-type stars are the most abundant in the galactic stellar population. These stars, with a similar internal structure to the Sun, are expected to have solar-like atmospheres. Investigating the stellar parameters and chemical abundances on late-type stars is essential to provide valuable constraints about stellar age, chemical evolution, and atmosphere of exoplanets. In this work, we present the study of the Near-UV and optical spectroscopic observation of three late-type stars: HR 8038, AC Her, and HD 76446, as obtained from the 36-inch MIRA/Oliver Observing Station. We derived surface temperature, gravity, metallicity, and the chemical abundances of light element Carbon in the stellar atmosphere. The elemental abundance of the Carbon for HR 8038, AC Her, and HD 76446 are derived to be 95%, 97%, and 108%, respectively, of the solar value., Comment: 10 pages, 2 figures, 2 tables, accepted for publication in Bulletin de la Soci\'et\'e Royale des Sciences de Li\`ege (BSRSL)

In a general set-up that allows unmeasured confounding, we show that the conditional average treatment effect on the treated can be identified as one of two possible values. Unlike existing causal inference methods, we do not require an exogenous source of variability in the treatment, e.g., an instrument or another outcome unaffected by the treatment. Instead, we require (a) a nondeterministic treatment assignment, (b) that conditional variances of the two potential outcomes are equal in the treatment group, and (c) a resistant population that was not exposed to the treatment or, if exposed, is unaffected by the treatment. Assumption (a) is commonly assumed in theoretical work, while (b) holds under fairly general outcome models. For (c), which is a new assumption, we show that a resistant population is often available in practice. We develop a large sample inference methodology and demonstrate our proposed method in a study of the effect of surface mining in central Appalachia on birth weight that finds a harmful effect.

We numerically study a discretized Vicsek model (DVM) with particles orienting in $q$ possible orientations in two dimensions. The study probes the significance of anisotropic orientation and microscopic interaction on the macroscopic behavior. The DVM is an off-lattice flocking model like the active clock model [ACM; EPL {\bf 138}, 41001 (2022)] but the dynamical rules of particle alignment and movement are inspired by the prototypical Vicsek model (VM). The DVM shows qualitatively similar properties as the ACM for intermediate noise strength where a transition from macrophase to microphase separation of the coexistence region is observed as $q$ is increased. But for small $q$ and noise strength, the liquid phase appearing in the ACM at low temperatures is replaced in the DVM by a configuration of multiple clusters with different polarization which does not exhibit any long-range order. We find that the dynamical rules have a profound influence on the overarching features of the flocking phase. We further identify the metastability of the ordered liquid phase subjected to a perturbation., Comment: 15 pages, 19 figures

We investigate the vibrational and magnetic properties of thin layers of chromium tribromide (CrBr$_3$) with a thickness ranging from three to twenty layers (3~L to 20~L) revealed by the Raman scattering (RS) technique. Systematic dependence of the RS process efficiency on the energy of the laser excitation is explored for four different excitation energies: 1.96 eV, 2.21 eV, 2.41 eV, and 3.06 eV. Our characterization demonstrates that for 12 L CrBr$_3$, 3.06~eV excitation could be considered resonant with interband electronic transitions due to the enhanced intensity of the Raman-active scattering resonances and the qualitative change in the Raman spectra. Polarization-resolved RS measurements for 12 L CrBr$_3$ and first-principles calculations allow us to identify five observable phonon modes characterized by distinct symmetries, classified as the A$_\textrm{g}$ and E$_\textrm{g}$ modes. The evolution of phonon modes with temperature for a 20 L CrBr$_3$ encapsulated in hexagonal boron nitride flakes demonstrates alterations of phonon energies and/or linewidths of resonances indicative of a transition between the paramagnetic and ferromagnetic state at Curie temperature ($T_\textrm{C} \approx 50$ K). The exploration of the effects of thickness on the phonon energies demonstrated small variations pronounces exclusively for the thinnest layers in the vicinity of 3 - 5 L. This observation is attributed to strong localization in the real space of interband electronic excitations, limiting the effects of confinement for resonantly excited Raman modes to atomically thin layers., Comment: 12 pages, 5 figures

Hard lattice problems are predominant in constructing post-quantum cryptosystems. However, we need to continue developing post-quantum cryptosystems based on other quantum hard problems to prevent a complete collapse of post-quantum cryptography due to a sudden breakthrough in solving hard lattice problems. Solving large multivariate quadratic systems is one such quantum hard problem. Unbalanced Oil-Vinegar is a signature scheme based on the hardness of solving multivariate equations. In this work, we present a post-quantum digital signature algorithm VDOO (Vinegar-Diagonal-Oil-Oil) based on solving multivariate equations. We introduce a new layer called the diagonal layer over the oil-vinegar-based signature scheme Rainbow. This layer helps to improve the security of our scheme without increasing the parameters considerably. Due to this modification, the complexity of the main computational bottleneck of multivariate quadratic systems i.e. the Gaussian elimination reduces significantly. Thus making our scheme one of the fastest multivariate quadratic signature schemes. Further, we show that our carefully chosen parameters can resist all existing state-of-the-art attacks. The signature sizes of our scheme for the National Institute of Standards and Technology's security level of I, III, and V are 96, 226, and 316 bytes, respectively. This is the smallest signature size among all known post-quantum signature schemes of similar security.

Hybrid star is the term given to a neutron star with a quark core. Due to a lot of uncertainties in the calculations and compositions of such a high-density system, it is of great interest and a preferred scenario for particle physicists and astrophysicists. To explore some novel aspects within the framework of the $5\mathcal{D}$ Einstein-Gauss-Bonnet(EGB) gravity, our current study presents a hybrid star model that includes strange quark matter in addition to regular baryonic matter. In hybrid stellar objects, a hadronic outer component surrounds a quark inner component, which prompts the consideration of the most basic MIT bag model equation of state to correlate the density and pressure of strange quark matter within the stellar interior, while radial pressure and matter density due to baryonic matter are connected by a linear equation of state. The model is constructed within the specifications of the Krori and Barua (KB) {\em ansatz} (Krori and Barua, J. Phys. A: Math. Gen. $\bold{8},508, 1975$). Here we present the solution for a particular compact object 4U 1538 - 52 with mass $\mathcal{M} = 0.87 \pm 0.07~\mathcal{M}_{\odot}$ and radius $\mathfrak{R} = 7.866_{-0.21}^{+0.21}$ km. We examine the fundamental physical characteristics of the star, which highlights how the values of matter variables are affected by the Gauss-Bonnet coupling parameter $\alpha$. Finally, as it meets all the physical requirements for a realistic model, we have come to realize that our present model is realistic., Comment: 23 pages, 12 figures, 4 tables, Final version published on 12.12.2023

Pre-trained models of source code have recently been successfully applied to a wide variety of Software Engineering tasks; they have also seen some practical adoption in practice, e.g. for code completion. Yet, we still know very little about what these pre-trained models learn about source code. In this article, we use probing--simple diagnostic tasks that do not further train the models--to discover to what extent pre-trained models learn about specific aspects of source code. We use an extensible framework to define 15 probing tasks that exercise surface, syntactic, structural and semantic characteristics of source code. We probe 8 pre-trained source code models, as well as a natural language model (BERT) as our baseline. We find that models that incorporate some structural information (such as GraphCodeBERT) have a better representation of source code characteristics. Surprisingly, we find that for some probing tasks, BERT is competitive with the source code models, indicating that there are ample opportunities to improve source-code specific pre-training on the respective code characteristics. We encourage other researchers to evaluate their models with our probing task suite, so that they may peer into the hidden layers of the models and identify what intrinsic code characteristics are encoded., Comment: Accepted to IEEE Transactions on Software Engineering. Extension of our previous paper "What do pre-trained code models know about code?" (ASE 2021, arXiv:2108.11308). 21 pages

The generation of controlled microstructures of functionalized nanoparticles has been one of the crucial challenges in nanoscience and nanotechnology. Efforts have been made to tune ligand charge states that can affect the aggregation propensity and modulate the self-assembled structures. In this work, we modelled zwitterionic Janus-like monolayer ligand-protected metal nanoclusters (J-MPCs) and studied their self-assembly using atomistic molecular dynamics and advanced enhanced sampling simulations. The oppositely-charged ligands functionalization on two hemispheres of a J-MPC elicits asymmetric solvation, primarily driven by distinctive hydrogen bonding patterns in the ligand-solvent interactions. Electrostatic interactions between the oppositely charged residues in J-MPCs guide the formation of one-dimensional and ring-like self-assembled superstructures with molecular dipoles oriented in specific patterns. The pertinent atomistic insights into the intermolecular interactions governing the self-assembled structures of zwitterionic J-MPCs obtained from this work can be used to design a general strategy to create tunable microstructures of charged MPCs., Comment: 17 pages, 4 figures