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visits member for 2 years, 7 months
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A mathematician, a programmer, etc. etc.


Apr
22
comment What's the name of this category
Isn't it isomorphic to the category $C_{A\times B}$?
Apr
20
awarded  Organizer
Apr
20
revised Why the $\zeta$ letter is like this?
Fixed tags
Apr
20
suggested approved edit on Why the $\zeta$ letter is like this?
Apr
20
comment Link between a topological space and a manifold
The topology is the collection of open sets of the space (by definition, a member of the topology is called an "open set"). But when a manifold "locally looks Euclidean", you're talking about charts...the image of a chart is itself an open set in the manifold, which requires a topology to talk about...
Apr
20
comment Why the $\zeta$ letter is like this?
@Goos, the difference is really negligible. Once you get one method of writing a zeta, it's not terribly difficult to deform the orthography into the one you desire. But starting with some zeta, I found, has been the hard part (for me anyways).
Apr
20
comment Why the $\zeta$ letter is like this?
foundalis.com/lan/hw/grkhandw.htm
Apr
18
awarded  Civic Duty
Apr
15
comment Solve $\sqrt{1+\sqrt{1-4x^2}}=x\left( 1+\sqrt{1+\sqrt{1+2\sqrt{1-4x^2}}}\right).$
Perhaps set $u=\sqrt{1-4x^{2}}$, so $x = \sqrt{1-u^{2}}/2$ and the problem becomes $2=\sqrt{1-u}(1+\sqrt{1+\sqrt{1+2u}})$...?
Apr
11
revised Evaluate $\int_{0}^{\pi/4}\frac{6 - 6\sin^{2}(x)}{2\cos^2(x)} \mathrm{d}x $
Improved the tex formatting
Apr
11
suggested approved edit on Evaluate $\int_{0}^{\pi/4}\frac{6 - 6\sin^{2}(x)}{2\cos^2(x)} \mathrm{d}x $
Apr
11
comment Evaluate $\int_{0}^{\pi/4}\frac{6 - 6\sin^{2}(x)}{2\cos^2(x)} \mathrm{d}x $
So...what have you attempted so far?
Mar
31
comment Tensor fields and vector bundles
To be precise, on the level of sections, don't we have an isomorphism $\Gamma(E\otimes F)\cong\Gamma(E)\otimes\Gamma(F)$ and not a strict equality?
Mar
31
comment Divergent Alternating Series
But if $p=1/2$ then $b_{9} = -1/2 < 0$, contradicting one of the premises of the problem ($b_{n}>0$ for all $n$).
Mar
30
comment Tangent space of the tangent bundle
Well...is $dg_{(x,0)}$ surjective?
Mar
10
revised Topological Quantum Field theories
Added some more explanation
Mar
8
comment Topological Quantum Field theories
@SanathDevalapurkar, also, where I'm studying -- I studied at UC Davis as an undergraduate. My current situation is rather strange (not that I'm private about it, I just cannot describe it in 140 characters!). I still study quantum gravity, though :)
Mar
8
comment Topological Quantum Field theories
In, e.g., 1+1 dimensional TQFT, dynamics is done by specifying the number of loops you begin with at time $t=0$, and how many you have at $t=1$, as well as the topology of the world-sheet for $0<t<1$. BUT the partition function (controlling dynamics) then becomes a function of the topological invariants (which invariants depends on the TQFT). This is good for, e.g., BF-theory since computing topological invariants is simpler than, say, solving the Wheeler-DeWitt equation :)
Mar
8
answered Topological Quantum Field theories
Mar
8
comment Topological Quantum Field theories
@SanathDevalapurkar, time reparametrization invariance forces the Hamiltonian to be a constraint; a great review of this can be found in Henneaux and Teitelboim's Quantization of Gauge Systems, viz. chapter 4.