Strong comparison principles for some nonlinear degenerate elliptic equations

In this paper, we obtain the strong comparison principle and Hopf Lemma for locally Lipschitz viscosity solutions to a class of nonlinear degenerate elliptic operators of the form ▽~2ψ + L(x, ▽ψ), including the conformal hessian operator.     

Extensions of the sewing lemma with applications

We give several extensions of the sewing lemma of Feyel and de La Pradelle and show how these results generalize Young’s integration theory in a simple and natural way. For illustrative purposes, we apply the lemma to integrals involving discontinuous functions of a fractional Brownian motion with the Hurst index $H>1∕2.$     

Spread of a catalytic branching random walk on a multidimensional lattice

For a supercritical catalytic branching random walk on ${\mathbb{Z}}^d$, $d\in \mathbb{N}$, with an arbitrary finite catalysts set we study the spread of particles population as time grows to infinity. It is shown that in the result of the proper normalization of the particles positions in the limit there are a.s. no particles outside the closed convex surface in ${\mathbb{R}}^d$ which we call the propagation front and, under condition of infinite number of visits of the catalysts set, a.s. there exist particles on the propagation front. We also demonstrate that the propagation front is asymptotically densely populated and derive its alternative representation.     

Decomposition of group rings and the converse of Schur’s lemma

In this work, we give necessary and su?cient conditions for a group ring (of finite group) to satisfy the converse of Schur’s lemma for group rings of finite groups. Rings considered here are commutative or noncommutative perfect. Some cases of twisted group rings are studied. Also we introduce the notion of semi-CSL ring.     

A generalization of Gale's lemma

In this work, we present a generalization of Gale's lemma. Using this generalization, we introduce two sharp combinatorial lower bounds for and , the two classic topological lower bounds for the chromatic number of a graph G.     

Singular Supercritical Trudinger–Moser Inequalities and the Existence of Extremals

In this paper, we present the singular supercritical Trudinger–Moser inequalities on the unit ball B in R~n, wher~e n ≥ 2. More precisely, we show that for any given α 0 and 0 t n, then the following two inequalities hold for ■,■.We also consider the problem of the sharpness of the constant α_(n,t). Furthermore, by employing the method of estimating the lower bound and using the concentration-compactness principle, we establish the existence of extremals. These results extend the known results when t = 0 to the singular version for 0 t n.     

广义山路引理的一些应用

具有(CPS)型条件的Ghoussoub-Preiss广义山路引理是经典的AmbrosettiRabinowitz山路引理的一个推广,本文将应用它来研究给定能量的具有对称性或非对称性势能的二阶哈密尔顿系统周期解的存在性.     

Infinitely many solutions for a class of sublinear Schrodinger equation

In this paper, we investigate the Schr\"{o}dinger equation, which satisfies that the potential is asymptotical 0 at infinity in some measure-theoretic and the nonlinearity is sublinear growth. By using variant symmetric mountain lemma, we obtain infinitely many solutions for the problem. Moreover, if the nonlinearity is locally sublinear defined for $|u|$ small, we can also get the same result. In which, we show that these solutions tend to zero in $L^{\infty}(\mathbb{R}^{N})$ by the Br\"{e}zis-Kato estimate.     

Representing (0, 1)-matrices by boolean circuits

A boolean circuit represents an n by n(0,1)-matrix A if it correctly computes the linear transformation over GF(2) on all n unit vectors. If we only allow linear boolean functions as gates, then some matrices cannot be represented using fewer than Ω(n²/lnn) wires. We first show that using non-linear gates one can save a lot of wires: any matrix can be represented by a depth-2 circuit with O(nlnn) wires using multilinear polynomials over GF(2) of relatively small degree as gates. We then show that this cannot be substantially improved: If any two columns of an n by n(0,1)-matrix differ in at least d rows, then the matrix requires Ω(dlnn/lnlnn) wires in any depth-2 circuit, even if arbitrary boolean functions are allowed as gates.