Log24

Tuesday, November 1, 2022

From “Goethe on All Souls’ Day”

Filed under: General — Tags: — m759 @ 3:04 am

The above title is that of a Log24 post on St. Cecilia's Day in 2017
that quoted some earlier All Souls' Day remarks from Berlin.

From that post —

Exercise:  Explain why the lead article in the November issue of
Notices of the American Mathematical Society  misquotes Weyl
and gives the misleading impression that the example above,
the eightfold cube ,  might be part of the mathematical pursuit
known as geometric group theory .

    Background:  Earlier instances here  of the phrase "geometric group theory." 

Monday, October 17, 2022

From the November 2022 Notices of the A.M.S.

Filed under: General — Tags: , , — m759 @ 9:28 am

"Geometric Group Theory" by Matt Clay, U. of Arkansas

"This article is intended to give an idea about how
the topology and geometry of a space influences
the algebraic structure of groups that act on it and
how this can be used to investigate groups."

Notices  homepage summary

A more precise description of the subject . . .

"The key idea in geometric group theory is to study
infinite groups by endowing them with a metric and
treating them as geometric spaces."

— AMS description of the 2018  treatise
Geometric Group Theory , by Drutu and Kapovich

See also "Geometric Group Theory" in this  journal.

The sort of thing that most interests me, finite  groups
acting on finite  structures, is not included in the above
description of Clay's article. That description only
applies to topological  spaces.  Topology is of little use
for finite  structures unless they are embedded* in 
larger spaces that are continuous, not discrete.

* As, for instance, the fifty-six 3-subsets of an 8-set are
embedded in the continuous space of The Eightfold Way .

Thursday, September 14, 2017

Group Actions

Filed under: General,Geometry — m759 @ 2:40 am

From this journal on the above publication date —

Related material — Geometric Group Theory in this journal.

Saturday, August 26, 2017

Aesthetic Distance

Filed under: General,Geometry — m759 @ 7:59 pm

Naive readers may suppose that this sort of thing is 
related to what has been dubbed "geometric group theory."

It is not. See posts now tagged Aesthetic Distance.

Sunday, July 30, 2017

Sermon: MS R I

Filed under: General,Geometry — Tags: — m759 @ 9:57 am

From Solomon's Cube

"Here MSRI, an acronym for Mathematical Sciences Research Institute,
is pronounced 'Misery.' See Stephen King [and] K.C. Cole . . . ."

From a manuscript by Mikhail Gromov cited yesterday in MSRI Program —

Quotes from a founder of geometric group theory

Saturday, July 29, 2017

MSRI Program

Filed under: General,Geometry — Tags: , — m759 @ 8:29 pm

"The field of geometric group theory emerged from Gromov’s insight
that even mathematical objects such as groups, which are defined
completely in algebraic terms, can be profitably viewed as geometric
objects and studied with geometric techniques."

— Mathematical Sciences Research Institute, 2016:

Geometric Group theory at MSRI (pronounced 'Misery')

See also some writings of Gromov from 2015-16:

For a simpler example than those discussed at MSRI
of both algebraic and geometric techniques applied to
the same group, see a post of May 19, 2017,
"From Algebra to Geometry." That post reviews
an earlier illustration —

For greater depth, see "Eightfold Cube" in this journal.

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