arXiv subjects

Cyril Malyshev

Publications and source records attributed to Cyril Malyshev.

7 recordsLinked to original sources

arXiv2021

How to Draw a Correlation Function

We discuss connection between the XX0 Heisenberg spin chain and some aspects of enumerative combinatorics. The representation of the Bethe wave functions via the Schur functions allows to apply the theory of symmetric functions to the calculation of the correlation functions. We provide a combinatorial derivation of the dynamical auto-correlation functions and visualise them in terms of nests of self-avoiding lattice paths. Asymptotics of the auto-correlation functions are obtained in the double scaling limit provided that the evolution parameter is large.

math-ph↗

arXiv2020

The partition function of the four-vertex model in inhomogeneous external field and trace statistics

The exactly solvable four-vertex model with the fixed boundary conditions in the presence of inhomogeneous linearly growing external field is considered. The partition function of the model is calculated and represented in the determinantal form. The established connection with the boxed plane partitions allows us to calculate the generating function of plane partitions with the fixed sums of their diagonals. The obtained results are another example of the connection of integrable models with the enumerative combinatorics.

cond-mat.stat-mech↗

arXiv2018

Correlation Functions as Nests of Self-Avoiding Paths

We discuss connection between the XXZ Heisenberg spin chain in the limiting case of zero anisotropy and some aspects of enumerative combinatorics. The representation of the Bethe wave functions via the Schur functions allows to apply the theory of symmetric functions to calculation of the correlation functions. We provide a combinatorial derivation of the dynamical correlation functions of the projection operator in terms of nests of self-avoiding lattice paths.

math-ph↗

arXiv2017

Zero Range Process and Multi-Dimensional Random Walks

The special limit of the totally asymmetric zero range process of the low-dimensional non-equilibrium statistical mechanics described by the non-Hermitian Hamiltonian is considered. The calculation of the conditional probabilities of the model are based on the algebraic Bethe ansatz approach. We demonstrate that the conditional probabilities may be considered as the generating functions of the random multi-dimensional lattice walks bounded by a hyperplane. This type of walks we call the walks over the multi-dimensional simplicial lattices. The answers for the conditional probability and for the number of random walks in the multi-dimensional simplicial lattice are expressed through the symmetric functions.

cond-mat.stat-mech↗

arXiv2017

The Einstein-like field theory and the dislocations with finite-sized core

Einstein-like Lagrangian field theory is developed to describe elastic solid containing dislocations with finite-sized core. The framework of the Riemann-Cartan geometry in three dimensions is used, and the core self-energy is expressed by the translational part of the general Lagrangian quadratic in torsion and curvature. In the Hilbert-Einstein case, the gauge equation plays the role of non-conventional incompatibility law. The stress tensor of the modified screw dislocations is smoothed out within the core. The renormalization of the elastic constants caused by proliferation of the dislocation dipoles is considered. The use of the singularityless dislocation solution modifies the renormalization of the shear modulus in comparison with the case of singular dislocations.

gr-qc↗

arXiv2014

Non-free gas of dipoles of non-singular screw dislocations and the shear modulus near the melting

The behavior of the shear modulus caused by proliferation of dipoles of non-singular screw dislocations with finite-sized core is considered. The representation of two-dimensional Coulomb gas with smoothed-out coupling is used, and the stress-stress correlation function is calculated. A convolution integral expressed in terms of the modified Bessel function $K_0$ is derived in order to obtain the shear modulus in approximation of interacting dipoles. Implications are demonstrated for the shear modulus near the melting transition which are due to the singularityless character of the dislocations.

cond-mat.mtrl-sci↗

arXiv2002

XX Heisenberg Spin Chain and an Example of Path Integral with "Automorphic" Boundary Conditions

New representation for the generating function of correlators of third components of spins in the XX Heisenberg spin chain is considered in the form given by the fermionic Gaussian path integrals. A part of the discrete anti-commuting integration variables is subjected to ``automorphic'' boundary conditions in respect of imaginary time. The situation when only a part of the integration variables is subjected to the unusual boundary conditions generalizes more conventional ones when ``automorphic'' boundary conditions appear for all sites in the lattice spin models. The results of the functional integration are expressed as determinants of the matrix operators. The generating function, as well as the partition function of the model, are calculated by means of zeta-regularization. Certain correlation functions at nonzero temperature are obtained explicitly.

hep-th↗