Geometric properties coded in the long-time asymptotics for the heat equation on

This paper investigates connections between the long-time asymptotics of heat distribution on a body in , and various geometric properties of , starting from an initially constant heat distribution supported on . We use combinatorial and differential geometric methods. We begin the paper with a result in .

     

Degenerate nonlocal Cahn-Hilliard equations: Well-posedness,regularity and local asymptotics

Existence and uniqueness of solutions for nonlocal Cahn-Hilliard equations with degenerate potential is shown. The nonlocality is described by means of a symmetric singular kernel not falling within the framework of any previous existence theory. A convection term is also taken into account. Building upon this novel existence result, we prove convergence of solutions for this class of nonlocal Cahn-Hilliard equations to their local counterparts, as the nonlocal convolution kernels approximate a Dirac delta. Eventually, we show that, under suitable assumptions on the data, the solutions to the nonlocal Cahn-Hilliard equations exhibit further regularity, and the nonlocal-to-local convergence is verified in a stronger topology.     

Well-posedness for the nonlocal nonlinear Schrödinger equation

We establish local well-posedness for small initial data in the usual Sobolev spaces Hs(R), s?1, and global well-posedness in H¹(R), for the Cauchy problem associated to the nonlocal nonlinear Schrödinger equation

     

Well-posedness for a higher-order Benjamin-Ono equation

In this paper we prove that the initial value problem associated to the following higher-order Benjamin-Ono equation

     

Well-posedness of stochastic Korteweg-de Vries-Benjamin-Ono equation

In this paper, we consider the stochastic Korteweg-de Vries-Benjamin-Ono equation with white noise. Using Fourier restriction norm method and some basic inequalities, we obtain a local existence and uniqueness result for the solution of this problem. We also get global existence of the L ²(ℝ) solution.     

Well-posedness and long-time behaviour for a singular phase field system of conserved type

In this paper, we study the well-posedness of a singular non-linearpartial differential equation system and the long-time behaviourof its solutions. Namely, an equation ruling the evolution ofthe absolute temperature of the system (recently introducedin BONETTI, E., COLLI, P., FABRIZIO, M. & GILARDI, G. (2006)Modelling and long-time behaviour for phase transitions withentropy balance and thermal memory conductivity. Discrete Contin.Dyn. Syst. Ser. B, 6, 1001–1026 (electronic) and BONETTI,E., COLLI, P., FABRIZIO, M. & GILARDI, G. (2007) Globalsolution to a singular integrodifferential system related tothe entropy balance. Nonlinear Anal., 66, 1949–1979) iscoupled with a generalization of the well-known Cahn–Hilliardequation for the order parameter . In particular, under suitableassumptions on the non-linearities involved, we prove that theelements of the -limit set (i.e. the cluster points) of thetrajectories solve the steady-state system that is naturallyassociated to the evolution problem.     

On long-time asymptotics of solutions of parabolic equations with increasing leading coefficients

Sharp sufficient conditions on the coefficients of a second-order parabolic equation are examined under which the solution of the corresponding Cauchy problem with a power-law growing initial function stabilizes to zero. An example is presented showing that the found sufficient conditions are sharp. Conditions on the coefficients of a parabolic equation are obtained under which the solution of the Cauchy problem with a bounded initial function stabilizes to zero at a power law rate.     

Well-posedness for a transport equation with nonlocal velocity

We study a one-dimensional transport equation with nonlocal velocity which was recently considered in the work of Córdoba, Córdoba and Fontelos [A. Córdoba, D. Córdoba, M.A. Fontelos, Formation of singularities for a transport equation with nonlocal velocity, Ann. of Math. (2) 162 (3) (2005) 1377-1389]. We show that in the subcritical and critical cases the problem is globally well-posed with arbitrary initial data in Hmax{3/2−γ,0}. While in the supercritical case, the problem is locally well-posed with initial data in H3/2−γ, and is globally well-posed under a smallness assumption. Some polynomial-in-time decay estimates are also discussed. These results improve some previous results in [A. Córdoba, D. Córdoba, M.A. Fontelos, Formation of singularities for a transport equation with nonlocal velocity, Ann. of Math. (2) 162 (3) (2005) 1377-1389].     

Well-posedness for the Kadomtsev-Petviashvili II equation and generalisations

We show the local in time well-posedness of the Cauchy problem for the Kadomtsev-Petviashvili II equation for initial data in the non-isotropic Sobolev space with and . On the scale this result includes the full subcritical range without any additional low frequency assumption on the initial data. More generally, we prove the local in time well-posedness of the Cauchy problem for the following generalisation of the KP II equation:

for , , and . We deduce global well-posedness for , and real valued initial data.

     

Well-posedness and persistence properties for the Novikov equation

Recently, Novikov found a new integrable equation (we call it the Novikov equation in this paper), which has nonlinear terms that are cubic, rather than quadratic, and admits peaked soliton solutions (peakons). Firstly, we prove that the Cauchy problem for the Novikov equation is locally well-posed in the Besov spaces (which generalize the Sobolev spaces Hs) with the critical index . Then, well-posedness in Hs with , is also established by applying Kato's semigroup theory. Finally, we present two results on the persistence properties of the strong solution for the Novikov equation.     

Global existence and long-time asymptotics for rotating fluids in a 3D layer

The Navier–Stokes–Coriolis system is a simple model for rotating fluids, which allows to study the influence of the Coriolis force on the dynamics of three-dimensional flows. In this paper, we consider the NSC system in an infinite three-dimensional layer delimited by two horizontal planes, with periodic boundary conditions in the vertical direction. If the angular velocity parameter is sufficiently large, depending on the initial data, we prove the existence of global, infinite-energy solutions with nonzero circulation number. We also show that these solutions converge toward two-dimensional Lamb–Oseen vortices as t→∞.     

Well-posedness and dynamics for the fractional Ginzburg-Landau equation

This article studies the global well-posedness and long-time dynamics for the nonlinear complex Ginzburg–Landau equation involving fractional Laplacian. The global existence and some uniqueness criterion of weak solutions are given with compactness method. To study the strong solutions with the semigroup method, we generalize some pointwise estimates for the fractional Laplacian to the complex background and study carefully the linear evolution of the equation. Finally, the existence of global attractors is studied.     

Improved intermediate asymptotics for the heat equation

This letter is devoted to results on intermediate asymptotics for the heat equation. We study the convergence towards a stationary solution in self-similar variables. By assuming the equality of some moments of the initial data and of the stationary solution, we get improved convergence rates using entropy/entropy-production methods. We establish the equivalence of the exponential decay of the entropies with new, improved functional inequalities in restricted classes of functions. This letter is the counterpart in a linear framework of a recent work on fast diffusion equations; see Bonforte et al. (2009) [18]. The results extend to the case of a Fokker–Planck equation with a general confining potential.     

Kink asymptotics of the perturbed sine-Gordon equation

The leading term and the first correction to the solution of the Goursat problem for the perturbed sine-Gordon equation are constructed at times of the order of the inverse of the perturbation parameter. The equation for the modulation of the first correction in the continuous spectrum is obtained.Institute of Mathematics with the Computational Center of the Bashkir Scientific Center of the Urals Branch of the Russian Academy of Sciences. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 93, No. 1, pp. 39–48, October, 1992.     

Well-posedness of second order evolution equation on discrete time

We characterize the well-posedness for second order discrete evolution equations in unconditional martingale difference spaces by means of Fourier multipliers and R-boundedness properties of the resolvent operator which defines the equation. Applications to semilinear problems are given.     

Well-posedness and blow-up phenomena for the generalized Degasperis-Procesi equation

In this paper, we mainly study the Cauchy problem of the generalized Degasperis-Procesi equation. We establish the local well-posedness and give the precise blow-up scenario for the equation. Then we show that the equation has smooth solutions which blow up in finite time.