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Sergey Leble

Publications and source records attributed to Sergey Leble.

32 records · Page 2Linked to original sources
arXiv2011

On quantum corrections to dislocations mass

Quasi-classical quantization of crystal dislocations field is considered in terms of functional integral. The generalized zeta-function is used to evaluate the functional integral and quantum corrections to mass in quasi-classical approximation. The quantum corrections to few classical solutions of one-dimensional Sin-Gordon model are evaluated with account of rest $n-1$ dimensions. The results are applied to appropriate crystal dislocation models.

quant-ph↗
arXiv2011

Quantum corrections to finite-gap solutions for Yang-Mills-Nahm equations via zeta-function technique

One-dimensional Yang-Mills-Nahm models are considered from algebrogeometric points of view. A quasiclassical quantization of the models based on path integral and its zeta function representation in terms of a Green function diagonal for a heat equation with an elliptic potential is considered. The Green function diagonal and, hence, zeta function and its derivative are expressed via solutions of Hermit equation and, alternatively, by means of Its-Matveev formalism in terms of Riemann teta-functions. For the Nahm model, which field is represented via elliptic (lemniscate) integral by construction, one-loop quantum corrections to action are evaluated as the zeta function derivative in zero point in terms of a hyperelliptic integral. The alternative expression should help to link the representations and continue investigation of the Yang-Mills-Nahm models. Keywords: Nahm model, one-loop quantum corrections, zeta function, elliptic potential, hyperelliptic integral, Its-Matveev formula. MSC numbers: 81Q30, 35J10, 35K08, 81T13.

math-ph↗
arXiv2010

Ultrashort opposite directed pulses dynamics

In this article we consider one dimensional model of an ultra short pulse propagation in isotropic dispersionless media taking into account a nonlinearity of the third order. We introduce a method for Maxwell's equations transformation based on a complete set of projecting operators. The operators generally correspond wave dispersion branches. As a simplest result of the method application we derive a system of equations describing dynamics of ultrashort pulses of opposite directions of propagation. We show that in such way the generalized Short Pulse Equations of Shafer and Wayne is obtained if the only directed wave is initialized. The effects of the unidirectional pulses interaction are traced.

physics.optics↗
arXiv2009

Quantum corrections to static solutions of Nahm equation and Sin-Gordon models via generalized zeta-function

One-dimensional Yang-Mills Equations are considered from a point of view of a class of nonlinear Klein-Gordon-Fock models. The case of self-dual Nahm equations and non-self-dual models are discussed. A quasiclassical quantization of the models is performed by means of generalized zeta-function and its representation in terms of a Green function diagonal for a heat equation with the correspondent potential. It is used to evaluate the functional integral and quantum corrections to mass in the quasiclassical approximation. Quantum corrections to a few periodic (and kink) solutions of the Nahm as a particular case of the Ginzburg-Landau (phi-in-quadro) and and Sin-Gordon models are evaluated in arbitrary dimensions. The Green function diagonal for heat equation with a finite-gap potential is constructed by universal description via solutions of Hermit equation. An alternative approach based on Baker-Akhiezer functions for KP equation is proposed . The generalized zeta-function and its derivative at zero point as the quantum corrections to mass is expressed in terms of elliptic integrals.

math-ph↗
arXiv2008

Quantum corrections to static solutions of phi-in-quadro and Sin-Gordon models via generalized zeta-function

A general algebraic method of quantum corrections evaluation is presented. Quantum corrections to a few classical solutions (kinks and periodic) of Ginzburg-Landau (phi-in-quadro) and Sin-Gordon models are calculated in arbitrary dimensions. The Green function for heat equation with a soliton potential is constructed by means of Laplace transformation theory and Hermit equation for the Green function transform. The generalized zeta-function is used to evaluate the functional integral and quantum corrections to mass in quasiclassical approximation.

quant-ph↗
arXiv2006

On quantum corrections to classical solutions via generalized zeta-function

A general algebraic method of quantum corrections evaluations is presented. Quantum corrections to a few classical solutions of Landau-Ginzburg model (phi-in-quadro) are calculated in arbitrary dimensions. The Green function for heat equation with soliton potential is constructed by Darboux transformation. The generalized zeta-function is used to evaluate the functional integral and corrections to mass in quasiclassical approximation. Some natural generalizations for matrix equations are discussed in conclusion.

quant-ph↗
arXiv2006

One-dimensional ultrasound propagation at stratified gas: Gross-Jackson model

The system of hydrodynamic-type equations, derived by two-side distribution function for a stratified gas in gravity field is applied to a problem of ultrasound. The theory is based on Gross-Jackson kinetic equation, which solution is built by means of locally equilibrium distribution function with different local parameters for molecules moving "up"and "down". The linearized version of the obtained system is studied and compared with other results and experiments at arbitrary Knudsen numbers. The problem of a generation by a moving plane in a rarefied gas is explored. The WKB solutions for ultrasound in a stratified medium are constructed in explicit form, evaluated and plotted.

physics.flu-dyn↗
arXiv2005

Darboux-covariant differential-difference operators and dressing chains

The general approach to chain equations derivation for the function generated by a Miura transformation analog is developing to account evolution (second Lax equation) and illustrated for Sturm-Liouville differential and difference operators. Polynomial differential operators case is investigated. Covariant sets of potentials are introduced by a periodic chain closure. The symmetry of the system of equation with respect to permutations of the potentials is used for the direct construction of solutions of the chain equations. A "time" evolution associated with some Lax pair is incorporated in the approach via closed t-chains. Both chains are combined in equations of a hydrodynamic type. The approach is next developed to general Zakharov-Shabat differential and difference equations, the example of 2x2 matrix case and NS equation is traced.

math-ph↗
arXiv2005

Piecewise continuous distribution function method: Fluid equations and wave disturbances at stratified gas

Wave disturbances of a stratified gas are studied. The description is built on a basis of the Bhatnagar -- Gross -- Krook (BGK) kinetic equation which is reduced down the level of fluid mechanics. The double momenta set is introduced inside a scheme of iterations of the equations operators, dividing the velocity space along and opposite gravity field direction. At both half-spaces the local equilibrium is supposed. As the result, the momenta system is derived. It reproduce Navier-Stokes and Barnett equations at the first and second order in high collision frequencies. The homogeneous background limit gives the known results obtained by direct kinetics applications by Loyalka and Cheng as the recent higher momentum fluid mechanics results of Chen, Rao and Spiegel. The ground state declines from exponential at the Knudsen regime. The WKB solutions for ultrasound in exponentially stratified medium are constructed in explicit form, evaluated and plotted.

physics.flu-dyn↗
arXiv2005

On integration of the closed KdV dressing chain

The dressing chain equations for the second order Sturm-Liouville differential operators is integrated. The simplest closure at the third step is linked to the spectral curve of the genus 1 and the explicit solution in elliptic Weierstrass functions is given. Dependence on integrals that enter the bihamiltonian structure is specified.

math-ph↗
arXiv2003

Sound velocity and acoustic nonlinearity parameter for fluids. Thermodynamic premises

New theoretical formulae of the sound velocity and the B/A nonlinearity parameter for some fluids are presented in the paper. Semi--ideal and van der Waals models of gas are considered and the parameters are compared to experiment data. The liquid water model for equation of state, given by Jeffery and Austin analytical equation, is considered also and modified on the basis of acoustic data .

physics.flu-dyn↗
arXiv2003

Covariant forms of Lax one-field operators: from Abelian to non-commutative

Links of factorization theory, supersymmetry and Darboux transformations as isospectral deformations are considered in the context of quantum theory. The infinite chain equations for factorizing operators for a spectral problem are derived. A closure of the chain defines a symmetry of the system. Examples of matrix-differential operators of Pauli and Dirac type are analyzed.

math-ph↗
arXiv2002

Generalized Zero Range Potentials and Multi-Channel Electron-Molecule Scattering

A multi-channel scattering problem is studied from a point of view of integral equations system. The system appears while natural one-particle wave function equation of the electron under action of a potential with non-intersecting ranges is considered. Spherical functions basis expansion of the potentials introduces partial amplitudes and corresponding radial functions. The approach is generalized to multi-channel case by a matrix formulation in which a state vector component is associated with a scattering channel. The zero-range potentials naturally enter the scheme when the class of operators of multiplication is widen to distributions. %Analog of multipolar expansion is treated. Spin variables, o Oscillations and rotations are incorporated into the scheme.

quant-ph↗