The Bethe-Salpeter equation plays a crucial role in understanding the physics of correlated fermions, relating to optical excitations solids as well resonances high-energy physics. Yet, it is notoriously difficult control numerically, typically requiring an effort that scales polynomially with energy and accuracy. This puts many interesting systems out computational reach. Using intermediate re...

In this paper, we consider the following linear Korteweg–de Vries–Benjamin Bona Mahony (KdV-BBM) equation on a finite interval.$ \left\{ \begin{array}{ll} u_t - a^2u_{xxt} + u_x u_{xxx} = 0, & (x, t)\in(0, L)\times (0, \infty), \\ u(0, t) u(L, u_x(L, &t\in u(x, 0) u_0(x), x \in L). \end{array} \right. $We show well-posedness by semigroup theory. A set of critical length $ \mathcal{L} is...

We consider an evolution equation similar to that introduced by Vese in [12] and whose solution converges in large time to the convex envelope of the initial datum. We give a stochastic control representation for the solution from which we deduce, under quite general assumptions that the convergence in the Lipschitz norm is in fact exponential in time.

We study the effective reduction for a nonlocal stochastic partial differential equation with oscillating coefficients. The operator in this is generator of non-Gaussian Levy processes, either integrable or non-integrable jump kernels. examine limiting behavior as scaling parameter tends to zero, and derive reduced (local nonlocal) equation. In particular, work leads an data assimilation system...

Let b and c be fixed coprime odd positive integers with min{b, c} > 1. In this paper, a classification of all positive integer solutions (x, y, z) of the equation 2 (x) + b (y) = c (z) is given. Further, by an elementary approach, we prove that if c = b + 2, then the equation has only the positive integer solution (x, y, z) = (1,1, 1), except for (b, x, y, z) = (89,13,1, 2) and (2 (r) - 1, r + ...

This article presents and analyzes an approximated exponential integrator for the (inhomogeneous) stochastic Manakov system. system of SPDE occurs in study pulse propagation randomly birefringent optical fibers. For a globally Lipschitz-continuous nonlinearity, we prove that strong order time is $ 1/2 $. then used to has convergence probability almost sure 1/2^{-} $, case cubic nonlinear coupli...

‎we study the existence of soliton solutions for a class of‎ ‎quasilinear elliptic equation in $mathbb{textbf{r}}^2$ with critical exponential growth‎. ‎this model has been proposed in the self-channeling of a‎ ‎high-power ultra short laser in matter‎.

‎‎In this paper, Solvability nonlinear Volterra integral equations with general vanishing delays is stated. So far sinc methods for approximating the solutions of Volterra integral equations have received considerable attention mainly due to their high accuracy. These approximations converge rapidly to the exact solutions as number sinc points increases. Here the numerical solution of nonlinear...