10,907 reputation
24876
bio website vmm.math.uci.edu
location Univ. of California at Irvine
age 84
visits member for 5 years, 2 months
seen May 14 at 20:21
I'm a Professor at UC Irvine, but spent most of my career at Brandeis. My research areas: Differential Topology, Transformation Groups, and Global Analysis. Recently I developed a math visualization program, 3D-XplorMath, freely available at http://3D-XplorMath.org) and a companion website, the Virtual Math Museum at http://VirtualMathMuseum.org. Last year I co-authored a differential equations text with my son Bob, most of which is downloadable from http://ode-math.com .

Sep
21
revised Definition of Sobolev spaces as a space of sections of certain type
Added a link to a copy of referenced work; deleted 1 characters in body; added 1 characters in body
Sep
20
answered Definition of Sobolev spaces as a space of sections of certain type
Sep
19
comment Collapsing of Riemannian manifolds with a group action
"...Consider the fixed point set F, it is of course a submanifold of M by the slice theorem". Note that it is really simpler than that; in geodesic coordinates at a point p of F, the fixed point set is locally the linear subspace left fixed by the linearized action at p.
Sep
15
comment First known proof of $\sqrt 2$ is irrational with prime factorization?
Your right Franz, it doesn't. It's just that there seems to be a belief that you NEED unique prime factorization to prove the irrationality of non-square integers, and when I first saw this (much more elementary) proof I found it an eye-opening experience.
Sep
14
answered First known proof of $\sqrt 2$ is irrational with prime factorization?
Sep
3
comment Area of union of random circles in a plane
You will probably get a more "natural" answer if you choose a "torus", i.e., identify opposite edges of a square, to eliminate edge effects.
Aug
31
awarded  Good Answer
Aug
29
awarded  Nice Answer
Aug
25
awarded  Enlightened
Aug
25
awarded  Nice Answer
Aug
25
revised Square root of a positive $C^\infty$ function.
improved citation
Aug
25
comment Square root of a positive $C^\infty$ function.
Yes, and functions of this type are discussed in section 2 of the reference I gave in my answer.
Aug
25
answered Square root of a positive $C^\infty$ function.
Aug
24
answered Measure theory treatment geared toward the Riesz representation theorem
Aug
16
awarded  Guru
Aug
15
awarded  Enlightened
Aug
15
awarded  Good Answer
Aug
15
comment About a letter by Richard Palais of 1965.
@Mariano: Yes, I guess that was a pretty verbose "no". :-) Dick
Aug
15
awarded  Nice Answer
Aug
15
answered About a letter by Richard Palais of 1965.