English
Related papers

Related papers: Hereditarily non-pythagorean fields

200 papers

We investigate finite field extensions of the unital 3-field, consisting of the unit element alone, and find considerable differences to classical field theory. Furthermore, the structure of their automorphism groups is clarified and the…

Rings and Algebras · Mathematics 2022-12-19 Steven Duplij , Wend Werner

We reduce the classification of finite extensions of function fields (of curves over finite fields) with the same class number to a finite computation; complete this computation in all cases except when both curves have base field…

Number Theory · Mathematics 2022-08-26 Kiran S. Kedlaya

We construct an infinite family of real cyclotomic fields with non-trivial class group. This result generalizes the result in [1] in the sense that our family includes theirs.

Number Theory · Mathematics 2022-05-17 Om Prakash

In this paper we find the genus field of finite abelian extensions of the global rational function field. We introduce the term conductor of constants for these extensions and determine it in terms of other invariants. We study the…

In this note we give a negative answer to Abraham Robinson's question whether a finitely generated extension of an undecidable field is always undecidable. We construct 'natural' undecidable fields of transcendence degree 1 over Q all of…

Logic · Mathematics 2013-11-07 Jochen Koenigsmann

We show that if two division $p$-algebras of prime degree share an inseparable field extension of the center then they also share a cyclic separable one. We show that the converse is in general not true. We also point out that sharing all…

Rings and Algebras · Mathematics 2015-03-10 Adam Chapman

We show that every finite group occurs as the automorphism group of infinitely many finite (field) extensions of any given Hilbertian field. This extends and unifies previous results of M. Fried and Takahashi on the global field case.

Number Theory · Mathematics 2017-12-19 François Legrand , Elad Paran

The aim of this note is to describe the structure of finite meadows. We will show that the class of finite meadows is the closure of the class of finite fields under finite products. As a corollary, we obtain a unique representation of…

Rings and Algebras · Mathematics 2011-11-10 Inge Bethke , Piet Rodenburg

We prove that a complete local or graded one-dimensional domain of prime characteristic has finite F-representation type if its residue field is algebraically closed or finite, and present examples of a complete local or graded…

Commutative Algebra · Mathematics 2010-01-13 Takafumi Shibuta

Let $\mathbb{K}$ be the algebraic closure of a finite field $\mathbb{F}_q$ of odd characteristic $p$. For a positive integer $m$ prime to $p$, let $F=\mathbb{K}(x,y)$ be the transcendency degree $1$ function field defined by…

Algebraic Geometry · Mathematics 2017-01-10 Gábor Korchmáros , Maria Montanucci , Pietro Speziali

In this paper we obtain the extended genus field of a global field. First we define the extended genus field of a global function field and we obtain, via class field theory, the description of the extended genus field of an arbitrary…

We examine situations, where representations of a finite-dimensional $F$-algebra $A$ defined over a separable extension field $K/F$, have a unique minimal field of definition. Here the base field $F$ is assumed to be a $C_1$-field. In…

Representation Theory · Mathematics 2019-02-20 Dave Benson , Zinovy Reichstein

We exhibit some new families of cyclotomic fields which have non-trivial plus parts of their class numbers. We also prove the $3$ - divisibility of the plus part of the class number of another family consisting of infinitely many cyclotomic…

Number Theory · Mathematics 2023-10-12 Kalyan Chakraborty , Azizul Hoque

It is known that sometimes a Belyi pair is not defined over its field of moduli. Instead, it is defined over a finite degree extension of its field of moduli, called a field of definition. We show that given a number $m$ there exists a…

Algebraic Geometry · Mathematics 2023-04-21 Alexander Molyakov

Let $k$ be an uncountable algebraically closed field and let $A$ be a countably generated left Noetherian $k$-algebra. Then we show that $A \otimes_k K$ is left Noetherian for any field extension $K$ of $k$. We conclude that all subfields…

Rings and Algebras · Mathematics 2007-05-23 Jason P. Bell

A graded-division algebra is an algebra graded by a group such that all nonzero homogeneous elements are invertible. This includes division algebras equipped with an arbitrary group grading (including the trivial grading). We show that a…

Rings and Algebras · Mathematics 2019-12-30 Yuri Bahturin , Alberto Elduque , Mikhail Kochetov

This paper is concerned with the problem of determining the number of division algebras which share the same collection of finite splitting fields. As a corollary we are able to determine when two central division algebras may be…

Rings and Algebras · Mathematics 2010-01-22 Daniel Krashen , Kelly McKinnie

Pseudo algebraically closed, pseudo real closed, and pseudo $p$-adically closed fields are examples of unstable fields that share many similarities, but have mostly been studied separately. In this text, we propose a unified framework for…

Logic · Mathematics 2024-07-17 Samaria Montenegro , Silvain Rideau-Kikuchi

The tilting correspondence is a fundamental property of perfectoid fields. In this note, we show that the tilting construction can also be used to detect perfectoid fields among nonarchimedean fields. In particular, for $K$ a complete…

Number Theory · Mathematics 2023-01-24 Ehsan Shahoseini , Kiran S. Kedlaya

We construct a class of finite rank multiplicative subgroups of the complex numbers such that the expansion of the real field by such a group is model-theoretically well-behaved. As an application we show that a classification of expansions…

Logic · Mathematics 2017-01-24 Erin Caulfield