7,267 reputation
2252
bio website
location
age
visits member for 5 years, 1 month
seen 7 hours ago

2d
comment Growth of the number of generators in hyperbolic groups
The existence of hyperbolic HNN extensions (eg some free-by-cyclic groups) makes this tricky. Does it help to assume that the hyperbolic group has trivial abelianization?
Dec
21
awarded  Necromancer
Dec
21
comment Do geodesics in SL2R map to geodesics in the hyperbolic plane?
Can ballistic curves be reparameterized to become geodesics? (Perhaps allowing variable speed?)
Dec
21
comment Do geodesics in SL2R map to geodesics in the hyperbolic plane?
Geodesics that point in the direction of the SO(2) subgroup cannot map to geodesics. I believe that these map to the constant path. If so, do you allow the constant path as a geodesic?
Dec
21
revised Quotient of the hyperbolic plane with respect to commutator group of $\pi_1(\Sigma_g)$
translated from notation of OP
Dec
21
revised Quotient of the hyperbolic plane with respect to commutator group of $\pi_1(\Sigma_g)$
fixed typo and wording
Dec
21
awarded  Revival
Dec
21
revised Quotient of the hyperbolic plane with respect to commutator group of $\pi_1(\Sigma_g)$
edited tags.
Dec
21
answered Quotient of the hyperbolic plane with respect to commutator group of $\pi_1(\Sigma_g)$
Dec
18
reviewed Approve Rooks in three dimensions
Dec
13
answered Dilatation of surface diffeomorphisms
Dec
6
reviewed Approve Question regarding Laplace equation under Evans setting
Nov
24
comment Additivity of simplicial volume
Thilo Kuessner's thesis should have a self-contained account. However, it does not appear to be easily available on-line. Perhaps contact him directly.
Nov
24
comment Additivity of simplicial volume
A small error in what you write -- a torus cannot appear in the geodesic boundary of a hyperbolic manifold. Perhaps you mean cusp.
Nov
23
revised Realizing proper pure octonions as conjugates
Removed reference to "dance of seven veils".
Nov
10
awarded  Yearling
Nov
9
comment Fantastic properties of Z/2Z
Oh, that looks nice - I'll have to think about that. By the way, I sort of want to edit your answer: $Z_2 * Z_2$ is the only non-trivial free product that is two-ended (thus is virtually cyclic) while all others have infinitely many ends (so contain rank two free groups, etc).
Nov
9
comment Fantastic properties of Z/2Z
There are several nice identities - the simplest after a few moments thought is $[x^2, y^2]$.
Nov
9
reviewed Approve Exploiting the Linearity of the Pullback
Nov
7
answered Unseparability of two linked rings in higher dimensions