arXiv subjects

Vaibhav Wasnik

Publications and source records attributed to Vaibhav Wasnik.

15 recordsLinked to original sources

arXiv2026

Correlator-Level Verification of Mass and Current Maps in Abelian Chern-Simons Dualities

We construct an explicit local operator realization that reproduces Dirac fermion correlation functions in three spacetime dimensions within an Abelian Chern-Simons framework and use it to examine the conjectured operator and deformation maps of fermion-boson duality directly at the level of correlation functions. We show that the predicted relation between bosonic and fermionic mass deformations, including the relative sign, is realized quantitatively, and that the fermionic U(1) current coincides with the topological gauge current inside correlation functions at the infrared fixed point. These results provide a direct correlator-level verification of key features of Abelian Chern-Simons dualities, going beyond arguments based solely on phase structure, anomaly matching, or large-N considerations.

hep-th↗

arXiv2026

A four-dimensional conformal construction of Virasoro-Shapiro amplitudes

We construct a four-dimensional conformal amplitude whose four-point structure matches the Virasoro-Shapiro form familiar from string theory. The construction uses only general principles of conformal field theory - radial quantization, scale invariance, and analyticity - and does not rely on worldsheet geometry or string degrees of freedom. The resulting object is a kinematical, first quantized amplitude defined by symmetry and consistency, providing a four-dimensional realization of stringlike analytic structure and a concrete target for amplitude bootstrap approaches.

hep-th↗

arXiv2025

Limitations to Chemotactic Concentration Sensing during $Ca^{2+}$ Signaling

Living cells sense noisy biochemical signals crucial for survival, yet models incorporating intracellular signaling are limited. This study examines how cells sense chemotactic concentrations through phosphorylation readouts in Ca2+ signaling, which is ubiquitous in most eukaryotic cells. Using stochastic simulations and analytical calculations we find that concentration sensing remains robust to variations in cytoplasmic reaction rates once they exceed a certain value, suggesting a potential evolutionary advantage that allows cells to optimize other signaling tasks without compromising concentration sensing accuracy. Our analysis demonstrates theoretically that Dictyostelium is capable of sensing very low concentrations of cyclic adenosine monophosphate (cAMP) as is experimentally seen.

q-bio.SC↗

arXiv2025

On the Limits of the Thermofield-Double Interpretation of the Minkowski Vacuum

The Minkowski vacuum is often presented in textbooks and reviews as a thermofield double (TFD) state, an entangled state of field modes in the left and right Rindler wedges. This picture is widely used to explain the Unruh effect, motivate entanglement entropy calculations, and connect quantum field theory to black hole thermodynamics and AdS/CFT. However, we show that this interpretation, while elegant, is not exact. We explicitly compute two-point functions and their derivatives for a massless scalar field in two-dimensional Minkowski space, comparing results obtained from canonical quantization with those obtained by assuming a TFD form of the vacuum. Mixed-derivative correlators agree perfectly, but higher-derivative correlators show systematic mismatches that persist even for points well away from horizons and are not removed by infrared regularization. To further test this picture, we construct an alternate coordinate system that divides Minkowski spacetime into two disconnected regions, apply the same derivation that leads to the standard TFD expression, and obtain a new "entangled-state" representation of the vacuum that is not thermal. This demonstrates that the appearance of a TFD structure is a feature of the derivation method rather than a fundamental property of the vacuum. Our results clarify the limits of interpreting the Minkowski vacuum as a literal TFD state, emphasizing that while it captures key thermal features, it should be viewed as a powerful calculational tool rather than a precise statement about Hilbert space structure.

gr-qc↗

arXiv2023

Accuracy in readout of glutamate concentrations by neuronal cells

Glutamate and glycine are important neurotransmitters in the brain. An action potential prop- agating in the terminal of a presynatic neuron causes the release of glutamate and glycine in the synapse by vesicles fusing with the cell membrane, which then activate various receptors on the cell membrane of the post synaptic neuron. Entry of Ca2+ through the activated NMDA receptors leads to a host of cellular processes of which long term potentiation is of crucial importance because it is widely considered to be one of the major mechanisms behind learning and memory. By analysing the readout of glutamate concentration by the post synaptic neurons during Ca2+ signaling, we find that the average receptor density in hippocampal neurons has evolved to allow for accurate measurement of the glutamate concentration in the synaptic cleft.

q-bio.NC↗

arXiv2023

Breakdown of additivity of transition rates in systems connected to multiple thermal reservoirs

In stochastic thermodynamics, it is commonly assumed that for a system coupled to multiple thermal reservoirs, the transition rates between two energy levels are additive across baths. In this work, we first demonstrate through an explicit construction of two subsystems-that are parts of a single composite system, each coupled to a distinct thermal reservoir-that while each subsystem individually evolves Markovianly, their joint evolution is inherently non-Markovian. We then present a general algebraic argument showing that, even if one assumes a Markovian description with additive transition rates, the steady-state condition imposed by the master equation leads to an inconsistency. The analysis identifies the precise structural limitation that arises in describing systems simultaneously interacting with multiple baths within a Markovian framework.

cond-mat.stat-mech↗

arXiv2022

Statistical physics of social networking

In this work we make an attempt to understand social networks from a mathematical viewpoint. In the first instance we consider a network where each node representing an individual can connect with a neighbouring node with a certain probability along with connecting with individuals who are friends of friends. We find that above a particular value of a chosen combination of parameters, the probability of connection between two widely separated nodes is a scale free. We next consider a simplified case of online social media networks in which each individual adds at a friends at constant probability per unit time: friends from a suggested neighbourhood as well as from his/her friendlist. We find that in the limit of large times since formation of the network, the probability of connection between two widely separated individuals is a scale free quantity. We hence, demonstrate a different scale free facet of networks not discussed before in literature.

physics.soc-ph↗

arXiv2022

Limitations on concentration measurements and gradient discerning times in cellular systems

This work reports on two results. At first we revisit the Berg and Purcell calculation that provides a lower bound to the error in concentration measurement by cells, by considering the realistic case when the cell starts measuring the moment it comes in contact with the chemoattractants, instead of measuring after equilibrating with the chemotactic concentration as done in the classic Berg and Purcell paper. We find that the error in concentration measurement is still the same as evaluated by Berg and Purcell. We next derive a lower bound on measurement time below which it is not possible for the cell to discern extra-cellular chemotactic gradients through spatial sensing mechanisms. This bound is independent of diffusion rate and concentration of the chemoattracts and is instead set by detachment rate of ligands from the cell receptors. The result could help explain experimental observations.

q-bio.SC↗

arXiv2022

Non Rindler horizons and radiating black holes

In this work we construct metrics corresponding to radiating black holes whose near horizon regions cannot be approximated by Rindler spacetime. We first construct infinite parameter coordinate transformations from Minkowski coordinates, such that an observer using these coordinates to describe spacetime events measures the Minkowski vacuum to be Planckian. Utilizing these results, we construct family of black holes that radiate at spatial infinity. As an illustration we study a subset of the black hole solutions that satisfy the null energy condition.

gr-qc↗

arXiv2021

Non supersymmetric femion boson symmetry

In this work we present symmetry transformations relating bosons to fermions which cannot be represented as a supersymmetric algebra. We present a symmetry transformation relating a complex scalar and a fermion in four dimensions and construct a theory defined by an action that respects the symmetry quantum mechanically. We next invoke gauge symmetry by adding a gauge field and a corresponding fermion and construct two different symmetry transformations with corresponding actions such that the corresponding theories respect the fermion boson symmetry transformations quantum mechanically. Unlike in a supersymmetric theory, the vacuum energy in the above theories could be negative. Phenomenological implications of the theories are open to research.

hep-th↗

arXiv2020

Average search time bound in cue based search strategy

In this work we consider the problem of searches that utilises past information gathered during searching, to evaluate the probability distribution of finding the source at each step. We start with a sample strategy where the movement at each step is in the immediate neighbourhood direction, with a probability proportional to the normalised difference in probability of finding the source with the present position source finding probability. We evaluate a lower bound for the average search time for this strategy . We next consider the problem of the lowerbound on any strategy that utilities information of the probability distribution evaluated by the searcher at any instant. We derive an expression for the same. Finally we present an analytic expression for this lower bound in the case of homogeneous diffusion of particles by a source. For a general probability distribution with entropy-E, we find that the lower bound goes as exp(E/2).

cond-mat.other↗

arXiv2019

Universality of scaling of correlations across probability distributions

Scale invariance and the resulting power law behaviours are seen in diverse systems. In this work we consider translation, rotational and scale invariant systems defined on a lattice, such that the variables defining the state at every lattice site take on the same range of finite values, with these values collectively picked up from probability distribution that can be arbitrary. We show that the exponent that describes the scaling of the two point correlation function in these systems will match the scaling exponent of a equilibrium statistical mechanical model described by a Boltzmannian distribution at criticality. This work therefore extends the concept of universality in statistical mechanics to probability distributions that do not have a Boltzmannian form.

cond-mat.stat-mech↗

arXiv2017

Issues in data expansion in understanding criticality in biological systems

At the point of a second order phase transition also termed as a critical point, systems display long range order and their macroscopic behaviors are independent of the microscopic details making up the system. Due to these properties, it has long been speculated that biological systems that show similar behavior despite having very different microscopics, may be operating near a critical point. Recent methods in neuroscience are making it possible to explore whether criticality exists in neural networks. Despite being large in size, many data sets are still only a minute sample of the neural system and methods towards expanding these data sets have to be considered in order to study the existence of criticality. In this work we develop an analytical method of expanding a dataset to the large N limit so that statements about the critical nature of the data set could be made. We also show using a particular dataset analyzed computationally in literature that expanding data sets keeping the moments of the original data set need not lead to unique values of the critical temperature when the large N limit is considered analytically, despite the mirage of them appearing to do so when analyzed computationally. This suggests that not all available data sets from experiments are amenable for understanding the critically of the underlying system.

q-bio.NC↗

arXiv2008

Is SUSY Natural?

Spacetime supersymmetry is widely believed to play an important role in most fundamental theories of physics, and is usually invoked in order to address problems of naturalness. In this paper, we examine the question of whether supersymmetry itself is ``natural'' (i.e., likely to exist as a fundamental component of nature at high energy scales). Our approach to answering this question is based on a statistical examination of the heterotic string landscape, and our conclusion is that supersymmetry is an exceedingly rare phenomenon. We also find that the likelihood of supersymmetry appearing at the string scale is dependent on the gauge symmetries present at the string scale, with certain gauge groups strongly favoring the appearance of N=1 supersymmetry and others not. This article summarizes several recent papers, yet also contains some new results. In particular, one new result is that the heterotic landscape appears to favor either the non-supersymmetric Standard Model or an N=1 SUSY GUT gauge group at the string scale; by contrast, the opposite outcomes (namely the MSSM or a non-supersymmetric GUT) are significantly disfavored.

hep-ph↗

arXiv2007

Supersymmetry versus Gauge Symmetry on the Heterotic Landscape

One of the goals of the landscape program in string theory is to extract information about the space of string vacua in the form of statistical correlations between phenomenological features that are otherwise uncorrelated in field theory. Such correlations would thus represent predictions of string theory that hold independently of a vacuum-selection principle. In this paper, we study statistical correlations between two features which are likely to be central to any potential description of nature at high energy scales: gauge symmetries and spacetime supersymmetry. We analyze correlations between these two kinds of symmetry within the context of perturbative heterotic string vacua, and find a number of striking features. We find, for example, that the degree of spacetime supersymmetry is strongly correlated with the probabilities of realizing certain gauge groups, with unbroken supersymmetry at the string scale tending to favor gauge-group factors with larger rank. We also find that nearly half of the heterotic landscape is non-supersymmetric and yet tachyon-free at tree level; indeed, less than a quarter of the tree-level heterotic landscape exhibits any supersymmetry at all at the string scale.

hep-th↗