Springer’s Odd Degree Extension Theorem for quadratic forms over semilocal rings

نویسندگان

چکیده

A fundamental result of Springer says that a quadratic form over field characteristic ≠2 is isotropic if it so after an odd degree extension. In this paper we generalize Springer’s theorem as follows. Let R be arbitrary semilocal ring, let S finite R-algebra constant degree, which étale or generated by one element, and q nonsingular R-quadratic whose base ring extension qS isotropic. We show then already

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Tits Indices over Semilocal Rings

We present a simplified version of Tits’ proof of the classification of semisimple algebraic groups, which remains valid over semilocal rings. We also provide explicit conditions on anisotropic groups to appear as anisotropic kernels of semisimple groups of a given index.

متن کامل

The Artin-springer Theorem for Quadratic Forms over Semi-local Rings with Finite Residue Fields

Let R be a commutative and unital semi-local ring in which 2 is invertible. In this note, we show that anisotropic quadratic spaces over R remain anisotropic after base change to any odd-degree finite étale extension of R. This generalization of the classical Artin-Springer theorem (concerning the situation where R is a field) was previously established in the case where all residue fields of R...

متن کامل

Witt's Extension Theorem for Mod Four Valued Quadratic Forms

The mod 4 valued quadratic forms defined by E. H. Brown, Jr. are studied. A classification theorem is proven which states that these forms are determined by two things: whether or not their associated bilinear form is alternating, and the rj-invariant of Brown (which generalizes the Arf invariant of an ordinary quadratic form). Particular attention is paid to a generalization of Witt's extensio...

متن کامل

Springer’s Theorem for Tame Quadratic Forms over Henselian Fields

A quadratic form over a Henselian-valued field of arbitrary residue characteristic is tame if it becomes hyperbolic over a tamely ramified extension. The Witt group of tame quadratic forms is shown to be canonically isomorphic to the Witt group of graded quadratic forms over the graded ring associated to the filtration defined by the valuation, hence also isomorphic to a direct sum of copies of...

متن کامل

Real Semigroups, Real Spectra and Quadratic Forms over Rings

real spectrum (ARS)finitely closed subset of, 52morphism of, 31projective limits of, 31residue space of, 66–69saturated subset of, 56subspace of, 61algebraLukasiewicz, 84Kleene, 87Post, 84AOSclosed subset, 210dependent subset, 210AOS-fan, 166archimedean-equivalent, 188ARS-fan, 170connected components, 208finiteisomorphi...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Indagationes Mathematicae

سال: 2021

ISSN: ['0019-3577', '1872-6100']

DOI: https://doi.org/10.1016/j.indag.2021.06.009