On some results of Lahiri

Using the idea of weighted sharing of values, we study the problem of uniqueness of meromorphic functions that share three values. The results in this paper improve all theorems given by Lahiri in Nagoya Math. J. 161 (2001) 193-206. Examples are provided to show that some results in this paper are sharp.     

On global Strichartz estimates for non-trapping metrics

We prove global Strichartz estimates (with spectral cutoff on the low frequencies) for non-trapping metric perturbations of the Schrödinger equation, posed on the Euclidean space.     

Dispersion and Strichartz estimates for some finite rank perturbations of the Laplace operator

We consider the dispersion properties in L^p spaces of Schrödinger hamiltonians with a large number of obstacles modelled by rank one perturbations. We obtain both for the dispersion an Strichartz estimates nonperturbative results with respect to the coupling constants.     

关于Strichartz的一个谱对准则

研究了与压缩迭代函数系和扩张迭代函数系相关的自仿测度的谱性质.在和谐对的条件下,分别确定了谱对形成的一些充分条件和必要条件.首先,给出了Strichartz谱对准则的几个等价形式.其次,得到了这个谱对成立的两个必要条件.最后,提供了Strichartz谱对准则的一个严格而详细的证明.     

On some formalized conservation results in arithmetic

I _n andB _n are well known fragments of first-order arithmetic with induction and collection for _n formulas respectively;I _n ⁰ andB _n ⁰ are their second-order counterparts. RCA₀ is the well known fragment of second-order arithmetic with recursive comprehension;WKL ₀ isRCA ₀ plus weak König's lemma. We first strengthen Harrington's conservation result by showing thatWKL ₀ +B _n ⁰ is ₁ ¹ -conservative overRCA ₀ +B _n ⁰ . Then we develop some model theory inWKL ₀ and illustrate the use of formalized model theory by giving a relatively simple proof of the fact thatI ₁ provesB _n+1 to be _n+2-conservative overI _n . Finally, we present a proof-theoretic proof of the stronger fact that the _n+2 conservation result is provable already inI ₀ + superexp. ThusI _n+1 proves 1-Con (B _n+1) andI ₀ +superexp proves Con (I _n )Con(B _n+1).The first author was partially supported by NSF Grant #DCR-860615     

On some results of Hua in short intervals

In this note, we prove some results of Hua in short intervals. For example, each sufficiently large integer N satisfying some congruence conditions can be written as

$ \left\{ {\begin{array}{*{20}{c}} {N = p_1^2 + p_2^2 + p_3^2 + p_4^2 + {p^k}}, \hfill \\ {\left| {{p_j} - \sqrt {N/5} } \right| \leqslant U,\left| {p - {{\left( {N/5} \right)}^{\tfrac{1}{k}}}} \right|\leqslant UN - \tfrac{1}{2} + \tfrac{1}{k},j = 1,2,3,4,} \hfill \\ \end{array} } \right. $

where \( U = N\tfrac{1}{2} - \eta + \varepsilon \) with \( \eta = \frac{2}{{\kappa \left( {K + 1} \right)\left( {{K^2} + 2} \right)}} \) and \( K = {2^{k - 1}},k\geqslant 3. \)

     

On some extremal connectivity results for graphs and matroids

Dirac and Halin have shown for n = 2 and n = 3 respectively that a minimally n-connected graph G has at least ((n–1)|V(G)|–2n)/(2n–1) vertices of degree n. This paper determines the graphs which are extremal with respect to these two results and, in addition, establishes a similar extremal result for minimally connected matroids.     

On some diophantine results related to Euler polynomials

In this paper we prove that there is at most one complex number b for which the shifted Euler polynomial E _n (x) + b has at most two zeros of odd multiplicity. Supported in part, by Grants T48791 and F68872 form HNFSR, and by the Hungarian Academy of Sciences.     

On some results of analysis for fuzzy metric spaces

A necessary and sufficient condition for a fuzzy metric space to be complete is given. We prove that a subspace of a separable fuzzy metric space is separable and every separable fuzzy metric space is second countable. Uniform limit theorem is generalized to fuzzy metric spaces.     

A critical case of Rallis inner product formula

Letπbe a genuine cuspidal representation of the metaplectic group of rank n.We consider the theta lifts to the orthogonal group associated to a quadratic space of dimension 2n+1.We show a case of regularised Rallis inner product formula that relates the pairing of theta lifts to the central value of the Langlands L-function ofπtwisted by a character.The bulk of this paper focuses on proving a case of regularised Siegel-Weil formula,on which the Rallis inner product formula is based and whose proof is missing in the literature.     

On some results of Morita and their application to questions of ampleness

We give an algebro-geometric proof of some results of Morita concerning the pull back of a cohomology class in the Jacobian fibration of a family of curves to the family itself. We apply those to the question of ampleness of line bundles on the family of curves and its symmetric products. Received: 3 April 2001; in final form: 1 October 2001/ Published online: 4 April 2002     

On some conditioning results in the probabilistic analysis of algorithms

A simple combinatorial approach is given for handling certain conditioning problems that arise in the probabilistic analysis of graph algorithms.     

On some global well-posedness and asymptotic results for quasilinear parabolic equations

We prove that the quasilinear parabolic initial-boundary value problem (1.1) below is globally well-posed in a class of high order Sobolev solutions, and that these solutions possess compact, regular attractors ast+.     

On connections between some selection and approximation results for multivalued maps

We study the general conditions on a family of values of a multivalued map under which the existence of single-valued approximations may be derived from continuous selection results.     

On some results of Yi and their applications in the functional equations

In this article, we establish some uniqueness theorems that improves some results of H. X. Yi for a family of meromorphic functions, and as applications, we give some results about the non-existence of meromorphic solutions of Fermat type functional equations.     

Strichartz Estimates for Non-selfadjoint Operators and Applications

Abstract

We prove Strichartz type estimates for non-selfadjoint pseudo-differential operators of order m with a curvature condition on the characteristic set. Local solvability results for the corresponding equations with L ^n/m potential (where n > m stands for the number of variables) and for the corresponding semi-linear equations with a non-linearity of order m/n ≤ α ≤ 2m/(n ? m) follow. This is achieved using a parametrix construction and a Brenner inequality for Fourier integral operators with complex phase.