Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: This Week's Finds in Mathematical Physics (Week 259)
Replies: 4   Last Post: Feb 29, 2008 8:15 AM

 Messages: [ Previous | Next ]
 Achim Blumensath Posts: 10 Registered: 6/21/05
Re: This Week's Finds in Mathematical Physics (Week 259)
Posted: Feb 29, 2008 8:15 AM

Hello,

John Baez wrote:
> In article <475d57b1\$0\$502\$b45e6eb0@senator-bedfellow.mit.edu>,
> <tchow@lsa.umich.edu> wrote:
>

>>Another way to understand the analogy between sets and vector spaces
>>is via the language of matroids. Sets correspond to "free matroids"
>>and vector spaces correspond to "representable matroids." How much
>>of what you say about the one-element field can be understood in
>>terms of matroids?

>
> I don't know, since I don't know much about matroids. But, from
> what little I know, a lot of projective geometry fits nicely into
> the matroid framework. That's promising, since the stuff I'm
> talking about is closely related to projective geometry.
>
> According to what you say, both for free matroids and "representable
> matroids" (whatever those are) over a given field we get one of these,
> up to isomorphism, for each natural number n - the cardinality or
> dimension. Are there other nice series of matroids, one for each
> natural number? That might lead to some fun stuff.

The following reference might contain an explanation of your
observation:

B. Zilber, Uncountably categorical theories. Transl. from the Russian
by D. Louvish. Transl. ed. by Simeon Ivanov. (English) Translations of
Mathematical Monographs. 117. Providence, RI: American Mathematical
Society. vi, 122 p. (1993). ISBN 0-8218-4586-1/hbk

One of the main results is the following:

Trichotomy Theorem: Every uncountably categorical theory is of one of
the following types, according to the geometries it realises:
(1) field-like
(2) module-like
(3) disintegrated

Examples are:
(1) algebraically closed fields
(2) vector spaces
(3) sets

Achim
--
________________________________________________________________________
| \_____/ |
Achim Blumensath \O/ \___/\ |
TU Darmstadt =o= \ /\ \|