"Quaternion algebras and quadratic forms"의 두 판 사이의 차이

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==introduction==
 
==introduction==
* let $F$ be a field
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* let <math>F</math> be a field
* consider a quaternion algebra defined by $F[i,j]/(i^2=a,j^2=b,ij=-ji)$
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* consider a quaternion algebra defined by <math>F[i,j]/(i^2=a,j^2=b,ij=-ji)</math>
 
* we denote it as  
 
* we denote it as  
$$\left(\frac{a,b}{F}\right)$$
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:<math>\left(\frac{a,b}{F}\right)</math>
* 4 dimensional algebra over $F$ with basis $1,i,j,k$ and multiplication rules <math>i^2=a</math>, <math>j^2=b</math>, <math>ij=-ji=k</math>.
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* 4 dimensional algebra over <math>F</math> with basis <math>1,i,j,k</math> and multiplication rules <math>i^2=a</math>, <math>j^2=b</math>, <math>ij=-ji=k</math>.
 
* it is an example of a central simple algebra (see [[Brauer group]])
 
* it is an example of a central simple algebra (see [[Brauer group]])
* it is either a division algebra or isomorphic to the matrix algebra of $2\times 2$ matrices over $F$: the latter case is termed split
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* it is either a division algebra or isomorphic to the matrix algebra of <math>2\times 2</math> matrices over <math>F</math>: the latter case is termed split
  
  
 
==quaternion algebra as a quadratic space==
 
==quaternion algebra as a quadratic space==
* let us consider the algebra $A=\left(\frac{a,b}{F}\right)$
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* let us consider the algebra <math>A=\left(\frac{a,b}{F}\right)</math>
* we regard it as a quadratic space associated with the quadratic form $(1,-a,-b,ab)$
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* we regard it as a quadratic space associated with the quadratic form <math>(1,-a,-b,ab)</math>
  
  
 
==Hilbert symbol==
 
==Hilbert symbol==
* In this case the algebra represents an element of order 2 in the [[Brauer group]] of $F$, which is identified with -1 if it is a division algebra and +1 if it is isomorphic to the algebra of 2 by 2 matrices.
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* In this case the algebra represents an element of order 2 in the [[Brauer group]] of <math>F</math>, which is identified with -1 if it is a division algebra and +1 if it is isomorphic to the algebra of 2 by 2 matrices.
  
  
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[[분류:math]]
 
[[분류:math]]
 
[[분류:migrate]]
 
[[분류:migrate]]
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==메타데이터==
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===위키데이터===
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* ID :  [https://www.wikidata.org/wiki/Q2835967 Q2835967]
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===Spacy 패턴 목록===
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* [{'LOWER': 'quaternion'}, {'LEMMA': 'algebra'}]

2021년 2월 17일 (수) 01:35 기준 최신판

introduction

  • let \(F\) be a field
  • consider a quaternion algebra defined by \(F[i,j]/(i^2=a,j^2=b,ij=-ji)\)
  • we denote it as

\[\left(\frac{a,b}{F}\right)\]

  • 4 dimensional algebra over \(F\) with basis \(1,i,j,k\) and multiplication rules \(i^2=a\), \(j^2=b\), \(ij=-ji=k\).
  • it is an example of a central simple algebra (see Brauer group)
  • it is either a division algebra or isomorphic to the matrix algebra of \(2\times 2\) matrices over \(F\): the latter case is termed split


quaternion algebra as a quadratic space

  • let us consider the algebra \(A=\left(\frac{a,b}{F}\right)\)
  • we regard it as a quadratic space associated with the quadratic form \((1,-a,-b,ab)\)


Hilbert symbol

  • In this case the algebra represents an element of order 2 in the Brauer group of \(F\), which is identified with -1 if it is a division algebra and +1 if it is isomorphic to the algebra of 2 by 2 matrices.


related items

expositions

메타데이터

위키데이터

Spacy 패턴 목록

  • [{'LOWER': 'quaternion'}, {'LEMMA': 'algebra'}]