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We introduce a framework for designing efficient diffusion models for $d$-dimensional symmetric-space Riemannian manifolds, including the torus, sphere, special orthogonal group and unitary group. Existing manifold diffusion models often…

Machine Learning · Computer Science 2025-05-29 Oren Mangoubi , Neil He , Nisheeth K. Vishnoi

Supersymmetric or Darboux transformations are used to construct local phase equivalent deep and shallow potentials for $\ell \neq 0$ partial waves. We associate the value of the orbital angular momentum with the asymptotic form of the…

Nuclear Theory · Physics 2009-11-10 Boris F. Samsonov , Fl. Stancu

Under investigation in this work is the robust inverse scattering transform of the discrete Hirota equation with nonzero boundary conditions, which is applied to solve simultaneously arbitrary-order poles on the branch points and spectral…

Mathematical Physics · Physics 2023-11-21 Guixian Wang , Xiu-Bin Wang , Bo Han

A review of solutions of solid-state diffusion problems in infinite and semi-infinite bodies is presented. Based on the identified solutions for the semi-infinite body a two-step diffusion problem is discussed in detail with the first step…

Materials Science · Physics 2023-02-09 Guglielmo Macrelli

We present new extensions to a method for constructing several families of solvable one-dimensional time-homogeneous diffusions whose transition densities are obtainable in analytically closed-form. Our approach is based on a dual…

Pricing of Securities · Quantitative Finance 2014-12-03 Giuseppe Campolieti , Roman N. Makarov

In a previous work[1] exact stable oblique soliton solutions were revealed in two dimensional nonlinear Schroedinger flow. In this work we show that single soliton solution can be expressed within the Hirota bilinear formalism. An attempt…

Pattern Formation and Solitons · Physics 2012-07-03 E. G. Khamis , A. Gammal

We construct families of bispectral difference operators of the form a(n)T + b(n) + c(n) T^{-1} where T is the shift operator. They are obtained as discrete Darboux transformations from appropriate extensions of Jacobi operators. We…

Classical Analysis and ODEs · Mathematics 2007-05-23 F. Alberto Grünbaum , Milen Yakimov

We study the existence of monotone traveling wave solutions in a class of nonclassical diffusion equations that include both standard diffusion and a higher-order mixed space-time dispersive term. The reaction term is nonlinear and subject…

Analysis of PDEs · Mathematics 2025-10-28 William Barker , Le Xuan Dong , Vu Trong Luong , Nguyen Duong Toan

In this paper a methodology is described to estimate multigroup neutron source distributions which must be added into a subcritical system to drive it to a steady state prescribed power distribution. This work has been motivated by the…

Nuclear Theory · Physics 2021-06-26 Leonardo , R. C. Moraes , Hermes Alves Filho , Ricardo C. Barros

The radiative transfer equation (RTE) arises in many different areas of science and engineering. In this paper, we propose and investigate a discrete-ordinate discontinuous-streamline diffusion (DODSD) method for solving the RTE, which is a…

Numerical Analysis · Mathematics 2016-11-23 Cheng Wang , Qiwei Sheng , Weimin Han

The double neutron-proton differential transverse flowtaken from two reaction systems using different isotopes of the same element is studied at incident beam energies of 400 and 800 MeV/nucleon within the framework of an isospin- and…

Nuclear Theory · Physics 2008-11-26 Gao-Chan Yong , Bao-An Li , Lie-Wen Chen

Two binary (integral type) Darboux transformations for the KdV hierarchy with self-consistent sources are proposed. In contrast with the Darboux transformation for the KdV hierarchy, one of the two binary Darboux transformations provides…

Exactly Solvable and Integrable Systems · Physics 2009-11-07 Yunbo Zeng , Wen-Xiu Ma , Yijun Shao

We study a diffuse interface model for the flow of two viscous incompressible Newtonian fluids in a bounded domain. The fluids are assumed to be macroscopically immiscible, but a partial mixing in a small interfacial region is assumed in…

Analysis of PDEs · Mathematics 2011-04-01 Helmut Abels

We develop a mathematical framework to analyze electrochemical impedance spectra in terms of a distribution of diffusion times (DDT) for a parallel array of random finite-length Warburg (diffusion) or Gerischer (reaction-diffusion) circuit…

Chemical Physics · Physics 2018-03-21 Juhyun Song , Martin Z. Bazant

We study a discrete Darboux transformation and construct the multi-soliton solutions in terms of ratio of determinants for integrable discrete sine-Gordon equation. We also calculate explicit expressions of single, double, triple, quad…

Exactly Solvable and Integrable Systems · Physics 2020-04-17 Y. Hanif , U. Saleem

In this work, we introduce a framework to design multidimensional Riemann solvers for nonlinear systems of hyperbolic conservation laws on general unstructured polygonal Voronoi-like tessellations. In this framework we propose two simple…

Numerical Analysis · Mathematics 2026-02-03 Elena Gaburro , Mario Ricchiuto , Michael Dumbser

The isospin diffusion and other irreversible phenomena are discussed for a two-component nuclear Fermi system. The set of Boltzmann transport equations, such as employed for reactions, are linearized, for weak deviations of a system from…

Nuclear Theory · Physics 2009-11-10 L. Shi , P. Danielewicz

Isothermic surfaces are surfaces which allow a conformal curvature line parametrisation. They form an integrable system, and Darboux transforms of isothermic surfaces obey Bianchi permutability: for two distinct spectral parameters the…

Differential Geometry · Mathematics 2022-05-31 Joseph Cho , Katrin Leschke , Yuta Ogata

A method is presented to obtain the change in the potential and in the relevant wavefunction of a linear system of ordinary differential equations containing a spectral parameter, when that linear system is perturbed and a finite number of…

Mathematical Physics · Physics 2022-10-12 Tuncay Aktosun , Mehmet Unlu

We develop a linear response formalism for nuclear spin diffusion in a dipolar coupled solid. The theory applies to the high-temperature, long-wavelength regime studied in the recent experiments of Boutis et al. [Phys. Rev. Lett. 92, 137201…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 D. Greenbaum , M. Kindermann , C. Ramanathan , D. G. Cory