Restricted Burnside group: Difference between revisions
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==Definition== | ==Definition== | ||
The '''restricted Burnside group''' <math>RB(n | The '''restricted Burnside group''' <math>RB(d,n)</math>, sometimes denoted <math>R(n,d)</math>, is defined as the [[quotient group]] by the [[finite residual]] of the [[Burnside group]] <math>B(d,n)</math>. In other words, it is the quotient of <math>B(n,d)</math> by the intersection of all [[normal subgroup of finite index|normal subgroups of finite index]] in it. | ||
Note that this group is a [[finite group]] if and only if the [[restricted Burnside problem]] for the pair <math>(n | Note that this group is a [[finite group]] if and only if the [[restricted Burnside problem]] for the pair <math>(d,n)</math> has the answer ''Yes''. | ||
==Facts== | ==Facts== | ||
* [[Kostrikin's theorem on restricted Burnside problem]]: For any [[prime number]] <math>p</math>, the group <math>RB( | * [[Kostrikin's theorem on restricted Burnside problem]]: For any [[prime number]] <math>p</math>, the group <math>RB(d,p)</math> is finite for every value of <math>n</math>. | ||
* The condition that this group be finite is ''weaker'' than the condition that the [[Burnside group]] <math>B(n,d)</math> be finite, i.e., there are many cases where <math>B(n | * The condition that this group be finite is ''weaker'' than the condition that the [[Burnside group]] <math>B(n,d)</math> be finite, i.e., there are many cases where <math>B(d,n)</math> is known to be infinite and <math>RB(d,n)</math> is known to be finite. This includes all odd primes greater than 665. | ||
* In those cases where < | * In those cases where <math>B(d,n)</math> is finite, <math>RB(n,d)</math> is isomorphic to <math>B(n,d)</math>. | ||
Revision as of 06:12, 13 April 2015
Definition
The restricted Burnside group , sometimes denoted , is defined as the quotient group by the finite residual of the Burnside group . In other words, it is the quotient of by the intersection of all normal subgroups of finite index in it.
Note that this group is a finite group if and only if the restricted Burnside problem for the pair has the answer Yes.
Facts
- Kostrikin's theorem on restricted Burnside problem: For any prime number , the group is finite for every value of .
- The condition that this group be finite is weaker than the condition that the Burnside group be finite, i.e., there are many cases where is known to be infinite and is known to be finite. This includes all odd primes greater than 665.
- In those cases where is finite, is isomorphic to .