1,276 reputation
1610
bio website rwoodroofe.math.msstate.edu
location Starkville, MS
age
visits member for 3 years
seen 2 days ago

Assistant Professor of Mathematics at Mississippi State University.


Dec
4
awarded  Yearling
Oct
5
answered Flag complexes that are shellable but not vertex decomposable
Sep
24
awarded  Autobiographer
Aug
30
comment Generalization of a theorem of Øystein Ore in group theory
There's also Roland Schmidt's nice book "Subgroup lattices of groups", which goes into a bit more depth on most of these and many related topics.
Aug
12
comment The Wedge Sum of path connected topological spaces
Link to amazon webpage for Hilton and Wylie is here: amazon.com/Homology-Theory-Introduction-Algebraic-Topology/dp/…
Jul
28
comment quasiprimitive non-solvable groups
John, that link looks wustl.edu specific. Try ams.org/mathscinet-getitem?mr=2661653 instead. (And no mathscinet access is required for that link.)
Jul
7
comment Factor subset of finite group
@Geoff Robinson: Yes, sounds like a good place to look for a possible counterexample.
May
31
comment Characterising extendable automorphisms
See also this related question mathoverflow.net/questions/7782/…
May
31
revised Characterising extendable automorphisms
commented on difficulty of problem; other minor edits
May
31
comment Characterising extendable automorphisms
The groupprops wiki has a couple of articles regarding this, e.g. groupprops.subwiki.org/wiki/Extensible_automorphisms_problem . While I found these to be rather incomplete, they give a start in finding some references.
May
31
answered Characterising extendable automorphisms
May
17
comment When is $S_n \times S_m$ a subgroup of $S_p$?
It's maybe worth pointing out that 6! / (5! \cdot 3!) is an integer (is 1), so you can't rule this out purely from the index of the subgroup.
May
2
comment Sylow 3-subgroups of symmetric group
See also en.wikipedia.org/wiki/Symmetric_group#Sylow_subgroups
Apr
17
comment $2$-group with two isomorphic normal subgroups of index $4$ with non-isomorphic quotients
This question has a somewhat similar flavor to mathoverflow.net/questions/153433/…
Mar
30
comment Which graphs generate a matroidal independence complex?
My favorite example is the cross polytope (i.e., generalized octahedron), which is the independence complex of the disjoint union of $K_2$'s.
Mar
28
comment What have simplicial complexes ever done for graph theory?
Matoušek's nice book "Using the Borsuk-Ulam theorem" should be mentioned here. It is a grad-student accessible, book-length treatment of the Lovász solution to the Kneser problem and more recent improvements (and all the background you need to understand them).
Mar
14
comment matroids axioms and independence system
@user47659: Yes, that's what I mean. It's easiest to prove if you focus on the (minimal) non-faces of $\Delta$ and the circuits of matroids, rather than the faces and independent sets. Here face == independent set, in different terminology.
Mar
12
answered matroids axioms and independence system
Feb
10
comment Classification of automorphism groups of groups of order $p^4$
Yes, StructureDescription is limited. But is there a better alternative for getting a human-readable description of groups, suitable for MathOverflow? (I guess one easy improvement would be to only ask for the structure of the outer automorphism group.)
Feb
10
answered Classification of automorphism groups of groups of order $p^4$