robot

1,647
Reputation
867 views
Is this your account?

Registered User 

Name robot
Member for 2 years
Seen 7 hours ago
Website
Location
Age
PhD student
23h
comment Equivariant $K$-theory, singular vectors, and flag manifolds
I meant the stuff about hyper-geometric functions. Sorry, I should have been more specific.
1d
comment Equivariant $K$-theory, singular vectors, and flag manifolds
OK. I just wonder whether the second paragraph can be pushed to generalized flag manifolds $G/P$ for $P$ parabolic. Do you know any references here? At least for the Borel case.
1d
comment Equivariant $K$-theory, singular vectors, and flag manifolds
You confused notation in the first paragraph. The bundle should be over $M$ and $H$ should be $B$. Is there any reason why don't you suppose that $G/B$ is a flag variety right from the beginning?
May
15
comment Continuation of homomorphisms of representations…
No need to restrict to complex representations. One just has to assume that the characteristic of the field does not divide the order of $G$.
Apr
29
comment Criterion for nilradical of a maximal parabolic subalgebra to be abelian?
bearspace.baylor.edu/Markus_Hunziker/www/… Lemma 2.2
Apr
10
comment Name for algebra and its tensor products
In that case you can just renumber indices $i \to i-1$ and write $U_i$, $i\in \mathbb{Z}_n$. Adding some context would be helpful. Are the variables $U_i$ (anti)commutative?
Apr
4
comment Density of smooth functions in Sobolev spaces on manifolds
I am only vaguely familiar with definition of Sobolev spaces on manifolds via patching local definitions. Thus it seems to me, that if you can prove the density locally, you have it also globally.
Apr
3
comment Invariance of dynamical system under a transformation
@Robert Bryant: I think that users are allowed to edit their posts only if they have high enough reputation. But maybe it applies only to questions and answers can be edited always.
Apr
3
comment Using Fourier Transform to speed up calculation of forces following an inverse square law
This could be also a good starting point: en.wikipedia.org/wiki/…
Apr
3
comment Using Fourier Transform to speed up calculation of forces following an inverse square law
First hit on google: cs.montana.edu/courses/spring2005/580/papers/…
Apr
3
revised Inversion of complex matrix
rewrite the equation
Mar
30
comment When does a modular form satisfy a differential equation with rational coefficients?
Perhaps this could be helpful. mmrc.iss.ac.cn/pub/mm25.pdf/7.pdf
Mar
30
comment Area of a lattice polygon in terms of its width
What is the question here?
Mar
29
asked easter problem - egg shapes
Mar
22
answered Inversion of complex matrix
Mar
22
comment simple roots of a reflection subgroup
I've emailed Hunziker about a week ago with no reply so far. I guess I should've cc'ed Enright as well.
Mar
22
revised simple roots of a reflection subgroup
edited tags
Mar
22
asked simple roots of a reflection subgroup
Mar
14
comment Hilbert Matrix and Approximation Theory
I believe that the answer to your question lies in the paper by Hilbert which you can find on the wikipedia page on Hilber matrix.
Mar
14
comment smooth connection on exterior power
Yes, it does. This question would be more appropriate for math.stackexchange.com
Mar
7
comment Invariant subbundles of tangent bundle of flag variety
Sorry for the jargon. I've edited my "answer" accordingly.
Mar
7
revised Invariant subbundles of tangent bundle of flag variety
fixed reference
Mar
6
answered Invariant subbundles of tangent bundle of flag variety
Feb
28
comment translation functors in parabolic category $\mathcal{O}$
Done. The link to (hopefully) improved question is above. Thank you for your time, I greatly appreciate it. Also, let me use this opportunity to thank you for your wonderful book on category $\mathcal{O}$. It is a truly great source of information!
Feb
28
revised translation functors in parabolic category $\mathcal{O}$
deleted 2940 characters in body; edited title
Feb
28
asked BGG-like resolutions and translations
Feb
28
comment translation functors in parabolic category $\mathcal{O}$
I think a better approach is to revert my question to the original version and create a new one.
Feb
28
revised translation functors in parabolic category $\mathcal{O}$
added 3054 characters in body; edited tags; edited title
Feb
28
revised translation functors in parabolic category $\mathcal{O}$
edited tags
Feb
27
comment Exceptional Schur-Weyl Duality
Already fixed. Thanks.
Feb
27
revised Exceptional Schur-Weyl Duality
wrong url in second link
Feb
27
answered Exceptional Schur-Weyl Duality
Feb
13
comment translation functors in parabolic category $\mathcal{O}$
Thank you for your comments. What if I view $\mathcal{O}^\mathfrak{p}_\lambda$ as a subcategory of $\mathcal{O}_\lambda$ and consider the restriction of the translation functor? My intended application is a cohomology formula for $L_\mathfrak{p}(\lambda+\mu)$ for $\mathfrak{g}$-integral $\lambda$ which is not $\mathfrak{g}$-dominant.
Feb
13
asked translation functors in parabolic category $\mathcal{O}$
Feb
11
comment From Topological to Smooth and Holomorphic Vector Bundles
Thanks a lot for your answer and for the ensuing discussion. These issues are usually swept under the rug in introductory courses and can get quite confusing later on.
Jan
27
comment Why are the holomorphic line bundle sections finite dimensional?
I think that the answer to your question lies in the theory of elliptic PDEs. All harmonic functions on a compact Riemannian manifold are constant and a proof of this fact is a matter of calculation. Nevertheless, this fact can be also (at least heuristically) gleaned from the mean value property of harmonic functions. If you want more details I suggest book by Raymond Wells - Differential Analysis on Complex Manifolds.
Jan
18
comment Infinite dimensional unitary representations of SU(2) for non-half-integer j?
@John Baez: Thanks for pointing this out! But I don't see that this is in fact an irreducible representation.
Jan
16
comment parabolic subalgebras and Cartan decomposition
Andrea, would you care to write these comments into an answer so I can award you the bounty?
Jan
16
comment parabolic subalgebras and Cartan decomposition
Agreed, but since he did not posted an answer I cannot give him the bounty. And thank you for your remarks.
Jan
10
comment Non-trivial representation of second-smallest dimension
Well, minimal was not the right word. What I meant to say that the representation with minimal dimension among all representations is the same as the representation which has the smallest dimension amongst fundamental representations.
Jan
10
comment Non-trivial representation of second-smallest dimension
It follows from the Weyl dimension formula that the fundamental representations have minimal dimensions. So you only have to check the dimensions of these.
Jan
8
comment parabolic subalgebras and Cartan decomposition
@Andrea Altomani: I don't know. Hence the bounty. :) By the way - how do you show that such a $\mathfrak{q}$ is a parabolic subalgebra?
Jan
3
comment parabolic subalgebras and Cartan decomposition
No, in my context $\theta$ is linear. The real parabolic subalgebras can come from different real versions of $G$.
Jan
3
comment parabolic subalgebras and Cartan decomposition
There is an abuse of notation. Cartan involution $\theta$ can mean an involution either on a real Lie group or on a real Lie algebra. Moreover you can always complexify the algebra and denote the extended involution by the same letter and still call it Cartan involution. You can extended it to a complex linear involution of the complexification or to a complex antilinear (i.e. $\theta (i X) = -i\theta(X)$) involution of the complexification. I've seen both and the authors still called their extension Cartan involution and denoted it by the same letter. Some authors use $\Theta$ at group level.
Jan
3
asked parabolic subalgebras and Cartan decomposition