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 Yearling
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  • 0 posts edited
  • 0 helpful flags
  • 4 votes cast
Nov
9
awarded  Yearling
Nov
9
accepted Existence of the double coset ring on paper of Ihara
Nov
9
asked Existence of the double coset ring on paper of Ihara
Nov
7
accepted recovering information about a group from the spectrum of its Cayley graph
Nov
6
comment is there a criterion for a two-generator subgroup of $PL(2,K)$ to be a cocompact lattice?
I would like to know how to prove that if $\gamma$ is an element of a torsion-free cocompact lattice in $PL(2,K)$ for $K$ a non-archimedean local field then the eigenvalues of $\gamma$ are in $K$. Ihara appears to make this claim in his article "Discrete subgroups of $PL(2,k_{\mathcal{P}})$.
Nov
6
asked recovering information about a group from the spectrum of its Cayley graph
Nov
6
comment is there a criterion for a two-generator subgroup of $PL(2,K)$ to be a cocompact lattice?
Yes, I apologise, I think I was mistaken. I was told that there was a criterion like this in Beardon's book "The Geometry of Discrete Groups" but I am having difficulty locating any result like that in the book.
Nov
6
awarded  Inquisitive
Nov
5
asked is there a criterion for a two-generator subgroup of $PL(2,K)$ to be a cocompact lattice?
Nov
4
asked In what sense is the function that maps $\alpha$ to the least $\alpha$-Erdős cardinal fast-growing
Oct
22
comment Homogeneous polynomials of degree 3 in two variables
I did have a motivation for asking the question. I was interested in a question about the uniqueness of Polish group topologies on a semi-direct product of a simple Lie group with a vector space over R via one of its faithful representations. I'm afraid I can't remember all the details of exactly how this question came up but it would have helped me to prove the existence of a unique Polish group topology for a certain semi-direct product of Lie groups.
Aug
3
comment roots in a root system which have nonzero coefficients with respect to each simple root
Is there any place on the internet or in the literature where all the roots in the $E_6$, $E_7$ or $E_8$ root systems are written out explicitly as linear combinations of simple roots?
Aug
3
accepted roots in a root system which have nonzero coefficients with respect to each simple root
Jul
31
asked roots in a root system which have nonzero coefficients with respect to each simple root
Jun
23
accepted Understanding how to construct Bruhat-Tits buildings for non-split groups by Galois descent
Jun
23
asked Understanding how to construct Bruhat-Tits buildings for non-split groups by Galois descent
Jun
1
asked artinian quotients of U(g)
May
19
asked Abelian subgroups of the automorphism group of a totally disconnected LCA group
May
2
awarded  Supporter
May
2
accepted Arithmetic quotients of Bruhat-Tits buildings for groups over local fields of positive characteristic