1,856 reputation
316
bio website
location London, United Kingdom
age 45
visits member for 2 years, 7 months
seen yesterday

Education: Mathematics BA, Theoretical Physics MSc

Interested in the Eastern & continental philosophy.


Sep
24
awarded  Autobiographer
Sep
13
answered Ways to think about vector bundle
Sep
13
comment Derivatives on Functors
@adeel:Yes, which is why I suppose he says in a 'loose' sense
Sep
13
answered Exercises in category theory for a non-working mathematican (undergrad)
Sep
13
comment Learning roadmap to Topological Quantum Field Theories from a mathematics perspective
The paper by Atiyah in 1988 where he states and motivates the axioms for TQFTs is short & useful.
Sep
13
comment What is linearity?
Its all of the above and more; there is what might be called a family resemblence between them; but there isn't a specific technical definition that will cover them all. The general 'philosophical' idea is that they are the sum of their parts, rather than than the sum being more than their parts.
Sep
9
accepted Are regular functions locally constant?
Sep
7
comment Is there a name for taking the pushforward (ie pushout) over the pullback?
@SanathDevalapurkar:its an interesting result which I wasn't aware of; but I am asking for something slightly different - in Dr Magidins terminology in his first diagram (which is the dual of the situation I am looking at here) then $Z \rightarrow X \times_T Y$ is not neccessarily isomorphism.
Sep
7
answered Newton 2nd law for rotations: $\tau = I \alpha$ dimensions correct?
Sep
7
comment Are regular functions locally constant?
And thanks for the insight.
Sep
7
comment Are regular functions locally constant?
A question is generally where one has some doubt; rather than where one has already recognised and understood; otherwise there little point to asking a question; that I've asked several questions on the same topic shows I'm struggling with the concept...its always generally easier in hindsight.
Sep
6
comment Can regular functions be specified simply as the sections of a bundle?
@Lin: ok, the map $p$ is not injective; so its not a homeomorphism and by your 'odd' result it can't be locally homeomorphic ie etale. That scotches this possibility.
Sep
6
comment Can regular functions be specified simply as the sections of a bundle?
@lin: that is interesting; how does that happen? Since the initial topology on just one map can be constructed by just pulling back the topology on the target, doesn't this mean they should always be homeomorphic?
Sep
6
asked Can regular functions be specified simply as the sections of a bundle?
Sep
6
asked Are regular functions locally constant?
Sep
6
comment Is there a name for spaces that always have local sections?
@studiosus: i thought as much; but then we have the inclusion of notions as fibre bundles < etale spaces < above notion; as you wrote 'hybrid' I supposed the loc.triv condition might be dropped.
Sep
6
comment Is there a name for spaces that always have local sections?
@studiosus: in a sense, yes; in locally trivial fibre bundles one can always locally lift through every point in a fibre; we don't need the fibre to be typical here so the same holds for locally trivial bundles; but for general fibre bundles or just bundles this won't hold.
Sep
5
comment Is there a name for spaces that always have local sections?
@studiosus:well, to be precise yes.
Sep
5
asked Is there a name for spaces that always have local sections?
Sep
4
comment Is there a name for taking the pushforward (ie pushout) over the pullback?
@magma: thanks, I forgot the title! ;).