bio | website | affinemess.com |
---|---|---|
location | Los Altos, CA | |
age | 45 | |
visits | member for | 4 years, 7 months |
seen | Apr 18 at 15:31 | |
stats | profile views | 3,543 |
Math Circler, ex-Googler and Dad. Now at Facebook.
Mar 16 |
comment |
Properties of Graphs with an eigenvalue of -1 (adjacency matrix)?
If G->B is a covering map (in the topological sense), then G inherits all the eigenvalues of B (just choose an eigenfunction that is uniform on the fibers). So, for instance, any graph which covers K_n for any n has -1 as an eigenvalue. The cycle of length 3k covers the triangle, which is another way to explain Kevin's example. |
Mar 16 |
awarded | Nice Answer |
Mar 16 |
awarded | Popular Question |
Mar 14 |
awarded | Enlightened |
Mar 14 |
awarded | Nice Answer |
Mar 12 |
comment |
Books you would like to see translated into English.
That's +10 from me, too. |
Mar 10 |
answered | A historical question: Hurwitz, Luroth, Clebsch, and the connectedness of M_g |
Mar 9 |
revised |
Why are the sporadic simple groups HUGE?
added 2 characters in body |
Mar 9 |
comment |
If 2^x and 3^x are integers, must x be as well?
This answer was given by Gerry. I just added the link to Wikipedia. |
Mar 9 |
revised |
If 2^x and 3^x are integers, must x be as well?
Added wikipedia link |
Mar 9 |
comment |
If 2^x and 3^x are integers, must x be as well?
Very interesting! Just to make sure I understand - does this generalize the "n^x for all n" version only, or can it be applied to "2,3,5" and "2,3" as well? |
Mar 9 |
accepted | If 2^x and 3^x are integers, must x be as well? |
Mar 9 |
comment |
If 2^x and 3^x are integers, must x be as well?
@jef: the best hint I can think of is "calculus of differences". |
Mar 9 |
awarded | Good Question |
Mar 9 |
awarded | Nice Question |
Mar 9 |
asked | If 2^x and 3^x are integers, must x be as well? |
Mar 8 |
comment |
Criteria for accepting an invitation to become an editor of a scientific journal
I think the following criterion is somewhat rational: when the publishers of a new journal solicit help for the editorial board, they understand that people will be asking themselves exactly the kind of question you are asking. Therefore they make an effort to establish the reputation of the new journal in the email - providing references to editors who have already joined, explaining why a new journal in this field is called for, contrasting it with similar journals etc. On the other hand they don't say anything about the submission process since this is completely irrelevant. |
Mar 6 |
answered | Teaching Methods and Evaluating them |
Mar 3 |
comment |
Diameter of m-fold cover
I must be missing something - why do you say that L(bi) < L(ai) in the second paragraph? Why is that a strict inequality? |
Feb 19 |
revised |
How should I approximate real numbers by algebraic ones?
deleted 1 characters in body |