436 reputation
16
bio website math.berkeley.edu/~ianagol
location Berkeley, CA
age
visits member for 1 year, 10 months
seen Apr 6 at 16:12

I'm a professor at UC Berkeley working predominantly in the field of low-dimensional topology.


Feb
6
comment Number of fixed order elements in the mapping class group of a closed surface
I think you should revise your question to ask for conjugacy classes of finite-order elements, of which there are finitely many, and they are enumerable. Otherwise, I would vote to close the question or shift it over to math.stackexchange
Dec
21
comment $x^x = y$, given $y$ solve for $x$ analytically
I can solve this for $y=e^{-\pi/2}$ :)
Aug
5
answered Degree of morphism of quotient of upper half-plane
Aug
4
answered Purpose of cusps
Aug
1
awarded  Student
Jul
31
asked Minimal number of moves to construct the challenges (circle packings and regular polygons) in Ancient Greek Geometry?
Jul
15
comment Different Riemannian manifolds with the same Riemannian volume form
For any given $g_1$, in each conformal class of $g_2$, there is a unique metric with the same volume form as $g_1$. So I suppose you could require $g_1$ and $g_2$ to lie in the same conformal class. In particular, a necessary condition for them to be equivalent is that they have the same conformal curvature invariants. In 2 dimensions, there are no conformal invariants. But in 3 dimensions, there is the Schouten tensor, and in 4 dimensions, the Weyl curvature. However, this will not be enough to concluded equivalence, for example if the Weyl tensor vanishes, since this is diffeo. invariant.
Jun
30
awarded  Yearling
Dec
26
answered Dehn presentation proof reference request
Dec
6
answered What is the most elegant proof of the Pythagorean theorem?
Oct
31
answered Structure of $x^2 + xy + y^2 = z^2$ integer quadratic form
Oct
30
answered Triangle inequality for hyperbolic distance
Oct
30
awarded  Supporter
Sep
30
answered fixed point of a parabolic commutator
Sep
30
answered Character Varieties- reference request
Sep
26
awarded  Revival
Jul
31
answered Hyperbolic triangle and two points in Poincare disk
Jul
27
awarded  Teacher
Jul
27
answered Limit sets of representations of once-punctured torus groups and circle packings
Jul
27
answered Can different uniformizations of Riemann surfaces be related somehow