Let k0 be a field of characteristic 0, and fix an algebraic closure k of k0. Let G be an algebraic k-group, and let Y be a G-k-variety. Let G0 be a k0-model (k0-form) of G. We ask whether Y admits a G0-equivariant k0-model. If Y admits a G- equivariant k0-model for...
The Generalized Langevin model representations of two second‐moment closure models for the rapid pressure‐strain term, proposed by Fu and Launder and by ... HA Wouters,TWJ Peeters,D Roekaerts - 《Physics of Fluids》 被引量: 64发表: 1996年 Non-realizability and ending laminations: Proof of...
In this procedure, an assumed quasi-periodic solution is expanded in a multi-frequency Fourier series and the governing ordinary differential equations of the nonlinear system are projected onto a finite set of Fourier modes. The arising nonlinear algebraic system is then solved with, e.g., the ...
The possibility of such a proof and related results demonstrate fundamental differences between the concepts of real and algebraic closures of fields.doi:10.1016/0022-4049(91)90110-NTomas SanderJournal of Pure and Applied AlgebraSander, T. (1991). Existence and uniqueness of the real closure of ...
one wants to find an action of G wherein a prescribed element and its inverse have attracting points with large basins of attraction, and the rate of attraction is somewhat uniform.;Tits' alternative has it that if the Zariski closure of a finitely generated linear group Gamma is semisimple,...
Mathematics - Algebraic Geometry14Q1068W30In this paper we show that not all affine rational complex surfaces can be parametrized birationally and surjectively. For this purpose, we prove that, if S is an affine complex surface whose projective closure is smooth, a necessary condition for S to...
The results of Artin and Schreier [1926] on ordered fields, presented in Sections 1 and 2, extend known properties of R and C and give new insights into the relationship of a field to its algebraic closure. The remaining sections study valuations and completions, which have become valuable ...