21,820 reputation
152120
bio website shef.ac.uk/nps
location Sheffield
age 48
visits member for 4 years, 9 months
seen Jul 18 at 12:51
I am an algebraic topologist, based at the University of Sheffield.

Jul
17
comment Intuition behind Kronecker's congruence?
What is $j$? If $Y$ is an indeterminate, how is $\alpha(Y)$ meaningful?
Jun
24
comment A question about the Leray-Serre spectral sequence
The Milnor hypersurfaces give a nice example of the phenomenon that @CraigWesterland mentioned. This is Example 3.3 in my notes at shef.ac.uk/nps/courses/bestiary/ss.pdf
Jun
4
comment Can we construct a Baas-Sullivan presentation of TMF?
As Tyler explains, you cannot get $tmf$ as a Baas-Sullivan quotient of $MU$. I do not know whether you could get it as a Baas-Sullivan quotient of $MO\langle 8\rangle$. That is an interesting question, but much harder to address because of the complicated structure of $\pi_*(MO\langle 8\rangle)$ and $\pi_*(tmf)$. My guess is that the answer is negative, but it would be nice to be proven wrong.
May
31
comment Nilpotency of BG^+
You should bear in mind the Kan-Thurston theorem: for any connected space $X$ there exists a group $G$ and a perfect subgroup $P$ such that $BG^+_P=X$.
May
27
answered classification of $p$-groups
May
22
answered K-groups of a permutative category - are they finite?
May
17
reviewed Leave Open Category = Groupoid x Poset?
May
17
reviewed Leave Open The classifying space of an infinite totally ordered set is contractible
May
17
comment The classifying space of an infinite totally ordered set is contractible
The two maps combine to give a poset map $\{0,1\}\times P\to Q$, and $B(\{0,1\}\times P)=[0,1]\times BP$.
May
17
comment The classifying space of an infinite totally ordered set is contractible
The space $BP$ is topologised as the colimit of the spaces $BQ$, as $Q$ runs over finite subsets of $P$. So a subset $F\subset BP$ is closed iff $F\cap BQ$ is closed with respect to the obvious topology on $BQ$, for all $Q$.
May
17
answered The classifying space of an infinite totally ordered set is contractible
May
14
comment What questions should -ologists of mathematics ask, in order to improve maths researcher training?
The link that you gave suggests that the project is focused on developing countries that do not already have a strong research culture. Answers in that context will be very different from answers in the more obvious context of US and European research universities. You should clarify which context you are interested in.
May
14
revised What questions should -ologists of mathematics ask, in order to improve maths researcher training?
Added text from the first link
May
12
reviewed Close Integral kernels of self-adjoint operators
May
12
reviewed Leave Open Can the image of a disk have nontrivial Hausdorff measure for $1 < d < 2$?
May
12
reviewed Leave Open Finite groups normalizing a torus
May
5
reviewed Leave Open Continuity of function mapping $\mathcal{P}(\mathcal{P}(X))$ to $\mathcal{P}(X)$
May
5
reviewed Leave Open If the quotient of an algebraic space $X$ by a finite group is a scheme, is $X$ a scheme?
May
5
reviewed Leave Open Reference request: Flipping the factors in the Künneth formula
May
2
awarded  Nice Answer