15,364 reputation
14184
bio website zakuski.math.utsa.edu/~jagy
location Berkeley, California
age 58
visits member for 5 years, 4 months
seen 5 hours ago
My main activity is in number theory of integral positive ternary quadratic forms. This began through years of working with Irving Kaplansky. Much of his unpublished writing on quadratic forms can be found as pdfs at http://zakuski.math.utsa.edu/~kap/forms.html and about Lie and Jordan superalgebras at http://zakuski.math.utsa.edu/~kap/superalgebra.html One of my own email addresses can be found easily using the search feature at http://www.ams.org/cml and just putting in my last name

May
24
comment Spherical cap is the only compact constant mean curvature surface bounded by a circle
Tom, your surfaces, dropping the compactness condition, are solutions of a second order ODE. Most of them need two circle boundaries to end up compact, for example an ordinary circular cylinder cut off at two circular ends. "In 1841 Delaunay proved that the only surfaces of revolution with constant mean curvature were the surfaces obtained by rotating the roulettes of the conics. These are the plane, cylinder, sphere, the catenoid, the unduloid and nodoid"
May
24
comment Spherical cap is the only compact constant mean curvature surface bounded by a circle
@YoavKallus, not compact, Riemann made a minimal surface of a sort of staircase shape, in every parallel plane the intersection with the surface is either a circle or a line.
May
20
revised On Polynomials dividing Exponentials
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May
20
revised On Polynomials dividing Exponentials
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May
20
revised On Polynomials dividing Exponentials
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May
20
comment On Polynomials dividing Exponentials
@GerryMyerson, Max Alekseyev has the second edition of the book, and says the corrected question reads $$ m^2 - 1 \; | \; 3^m + \left( n! - 2 \right)^m, $$ so it really is off by just a single number and was a typo in the first edition. Good to know.
May
20
comment On Polynomials dividing Exponentials
@MaxAlekseyev, aha! So it may really have been a typo in the first edition, just a single number different. That makes me feel a bit better about the authors; in 2010 I was less than charitable (then deleted some stuff here).
May
20
comment Theory of C* algebras over other fields than the complex numbers
@NateAckerman, did you have some specific title for an article that you cannot find? I refer to your MSE question math.stackexchange.com/questions/1290667/…
May
20
comment Theory of C* algebras over other fields than the complex numbers
@YemonChoi,see math.stackexchange.com/questions/1290667/… where it appears that Nate has found one or more citations of interest but is unable to get more detail
May
20
comment On Polynomials dividing Exponentials
@MaxAlekseyev, see one of my answers, I pasted in the page with the actual problem. I also put a link to the current (second) edition of the book, which I do not plan to purchase. Since the problem did not work out, they may simply have deleted it for the second edition without comment. For more information, it would be necessary to contact Andreescu or Dospinescu.
May
20
revised On Polynomials dividing Exponentials
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May
20
revised On Polynomials dividing Exponentials
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May
20
comment On Polynomials dividing Exponentials
@GerryMyerson, I fixed the link, however it points to a second edition of the book, which probably lacks this problem. I have a scanner, I imagine the thing to do is scan in the page from the first edition with this exact problem.
May
20
revised On Polynomials dividing Exponentials
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May
13
comment Explanation of the definition of Saturated Sets in Lambda Calculus
found it, mathoverflow.net/questions/89054/…
May
13
comment Explanation of the definition of Saturated Sets in Lambda Calculus
My best exchange on language here was a question where I said I was expired by a previous question rather than inspired by it. A French guy asked me if i were serious and said that the analogous phrase (inspired by) in French is also used too much.
May
13
comment Explanation of the definition of Saturated Sets in Lambda Calculus
urbandictionary.com/define.php?term=Delucidate although there seems to be a real word in Italian...
May
12
comment An algorithm for Poincare recurrence time
how do you do $$ \cos (t) + \cos (\sqrt{2} t) + \cos (\sqrt{3} t) > 3 - 10^{-9}? $$
May
11
comment What sort of models did Bolyai and Lobachevsky use to demonstrate the consistency of their models of non-Euclidean Geometry?
My take, from having published on this, is that Bolyai did not make any model in our sense, he predicted everything that had to happen and said he had created a new world. Gauss was less than gracious, having come to many of the same conclusions; I give Bolyai greater credit, he actually said this is it.
May
3
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