非线性不适定问题的正则化方法

本文考虑非线性不适定问题Tx=y的近似求解,利用Тихоноь正则化方法来逼近问题的x-极小模解,当算子和右端都近似已知时,给出一种决定正则化参数的方法,并给出正则解的收效性和渐近收敛阶估计。     

A characterization of total reflection orders

Let be a Coxeter system with set of reflections . It is known that if is a total reflection order for , then, for each , and its complement are stable under conjugation by . Moreover the upper and lower -conjugates of are still total reflection orders. For any total order on , say that is stable if is stable under conjugation by for each . We prove that if and all orders obtained from by successive lower or upper -conjugations are stable, then is a total reflection order.

     

Many countable support iterations of proper forcings preserve Souslin trees

We show that many countable support iterations of proper forcings preserve Souslin trees. We establish sufficient conditions in terms of games and we draw connections to other preservation properties. We present a proof of preservation properties in countable support iterations in the so-called Case A that does not need a division into forcings that add reals and those who do not.     

Ordinal arithmetic with simultaneously defined theta‐functions

This article provides a detailed comparison between two systems of collapsing functions. These functions play a crucial role in proof theory, in the analysis of patterns of resemblance, and the analysis of maximal order types of well partial orders. The exact correspondence given here serves as a starting point for far reaching extensions of current results on patterns and well partial orders. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim     

The crossing barrier of a non-homogeneous semi-Markov chain

In this paper, we derive the probability distribution function of the first entry time in a time varying subset of the phase space of a non-homogeneous semi-Markov chain. Deterministic and stochastic time varying subsets are considered and results with a ready algorithmic implementation are provided. A possible application is debated by defining and analysing deterministic and stochastic time variable level crossing order for semi-Markov chains.     

Rationalizations of choice functions

In this paper, we are interested in the connectios between the properties of binary relations and their associated choice functions. In particular, we analyze the properties of choice functions rationalized by certain irreflexive orders.     

Anisotropic equations in weighted Sobolev spaces of higher order

We consider the strongly nonlinear boundary value problem,