current community
chat
MathOverflow
MathOverflow Meta
your communities
Sign up
or
log in
to customize your list.
more stack exchange communities
company blog
Stack Exchange
Inbox
Reputation and Badges
sign up
log in
tour
help
Tour
Start here for a quick overview of the site
Help Center
Detailed answers to any questions you might have
Meta
Discuss the workings and policies of this site
MathOverflow
Questions
Tags
Users
Badges
Unanswered
Ask Question
Profile
Activity
katz
Meta User
Network Profile
Reputation
3,494
3.5k
2.9k
2.2k
May
Aug
Nov
Feb
Top tag
nonstandard-analysis
Next privilege
5,000 Rep.
Approve tag wiki edits
Badges
9
45
Newest
Custodian
Next badge
28/30
Inquisitive
Impact
~
77k
people reached
11 posts edited
3 helpful flags
215 votes cast
summary
answers
questions
tags
badges
favorites
bounties
reputation
all actions
86
Answers
newest
activity
votes
3
Taking “Zooming in on a point of a graph” seriously
Feb 28 '14 at 11:21
3
Transitive geodesics on closed surfaces of genus greater than one
Aug 6 '13 at 14:13
3
Was Desargues more an Euclid or an Eudoxos?
Apr 12 '13 at 8:47
3
Fixing a proof of the systolic inequality for higher genus surfaces
Apr 9 '13 at 11:00
2
Height function on 2-torus with only 3 critical points
Feb 3 at 7:50
2
What is… A Grossone?
Jan 31 at 14:01
2
Literature that helps explain what the theory of numerosities contributes with
Jan 5 at 18:00
2
Thurston geometries---the geometry of the universal cover of $SL(2, \mathbb{R})$
Dec 7 '15 at 19:34
2
Why do we teach calculus students the derivative as a limit?
Dec 22 '14 at 11:45
2
Why there are two point at infinity on certain elliptic curve
Dec 4 '14 at 17:45
2
Analogues of P vs. NP in the history of mathematics
Mar 14 '14 at 9:02
2
The Arnold – Serre debate
Feb 6 '14 at 18:41
2
Isoperimetric inequality on a Riemannian sphere
Sep 11 '13 at 13:40
2
Why can an infinite-order polynomial be written as the ratio of two finite-order polynomials?
Apr 18 '13 at 16:20
2
geometric interpretation of Lie bracket
Apr 17 '13 at 8:19
2
Non-ZFC set theory and nonuniqueness of the hyperreals: problem solved?
Apr 11 '13 at 12:02
2
Explaining the concept of projective space: notes for students
Apr 4 '13 at 13:27
2
Are all countable, nonstandard models of arithmetic given by ultrapowers?
Mar 11 '13 at 17:15
1
Circle Action on Quaternionic Projective Space
2 days ago
1
Strong equivalence between intrinsic and extrinsic metrics on $GL_n^+$?
Dec 29 '15 at 15:05
1
What is the modern consensus on the difficulty of infinitesimals?
Feb 2 at 13:50
1
Are all ideals I in the ring of smooth functions on a compact manifold M equal to a set of smooth functions that vanish in $Z \subset M$?
Jan 13 at 12:46
1
Does mathematical induction presuppose the existence of a completed infinity?
Dec 30 '15 at 7:53
1
How to prove Liouville measure is invariant under geodesic flow?
Dec 8 '15 at 13:12
1
Which universities teach true infinitesimal calculus?
Dec 28 '14 at 12:20
1
Survey of the history of calculus?
Aug 11 '14 at 10:30
1
Mathematical research published in the form of poems
May 11 '14 at 18:31
1
What is the definition of continuity of set-valued functions?
May 20 '13 at 15:00
1
Equidistant hypersurfaces in symmetric space via exponentiation?
Jul 24 '13 at 13:00
1
Equidistant hypersurfaces in symmetric space via exponentiation?
Jul 24 '13 at 10:17
MathOverflow works best with JavaScript enabled