1,407 reputation
1613
bio website code.google.com/p/notebk
location Los Angeles, CA
age
visits member for 2 years, 5 months
seen 10 hours ago

A mathematician, a programmer, etc. etc.

My interests are limited to classical general relativity, quantum gravity, mathematical aspects of quantum field theory, and related fields.


Oct
14
comment What is the difference between the compact U(1) group and non-compact U(1) group?
@WetSavannaAnimalakaRodVance Well, since $U(1)$ is the topological compactification of $\mathbb{R}$, topologically it makes sense to think of $(\mathbb{R}, +)$ as the "non-compact" version of $U(1)$.
Oct
10
revised Correspondence between one-parameter subgroups of $G$ and $T_eG$
Improved formatting
Oct
10
suggested suggested edit on Correspondence between one-parameter subgroups of $G$ and $T_eG$
Oct
3
comment QFT Hilbert spaces over other rings than the complex numbers $\mathbb{C}$
An article on a related topic, which may interest the OP, Twisted de Rham cohomology, homological definition of the integral and "Physics over a ring"...
Oct
1
answered Classical Hamiltonian involving product of factors whose quantum analogues don't commute
Sep
30
awarded  Explainer
Sep
25
answered Non-trivial solution for a linear set of coefficients involved in the phonon modes of a semiconductor quantum dot
Sep
25
comment Non-trivial solution for a linear set of coefficients involved in the phonon modes of a semiconductor quantum dot
@GeoffDiederich Is your definition of $\delta$ correct? Should the second factor's second term be $-kRj_{1}(kR)$ or $-kRj_{\ell}(kR)$?
Sep
24
awarded  Autobiographer
Sep
19
comment Why is the phase space a symplectic manifold rather than a manifold with a metric?
Minor stuff: (a) isn't it spelt "torsion-free"? Now for the major question: (b) I have forgotten, so this may be stupid, but isn't the lack of local invariants on a Symplectic manifold responsible for Darboux's theorem (more or less)?
Sep
16
comment Boundary term in Einstein-Hilbert action
Eric Poisson's lecture notes on Advanced General Relativity (pdf), which formed the basis of his book Relativist's Toolkit, discusses this (in chapter 4)...
Sep
4
revised A Conceptual Problem With the Field Equations of General Relativity
added Deser's paper reference
Sep
4
answered A Conceptual Problem With the Field Equations of General Relativity
Aug
30
answered Toy models of asymptotic safety?
Aug
26
comment Is there a general stress-energy tensor for vector fields?
@firtree minor detail: the expression quoted is for a massive and complex free scalar field, hence the $m$ and the $\bar{\phi}$ quantities. But that aside, you are correct.
Aug
26
comment Variational derivatives of strongly connected diagrams functional in gauge theory
@ACuriousMind, from what Google Translator tells me (and what pg 215 says), $K^{a}_{\mu}$ is the external source for $sA^{a}_{\mu}$ where $s$ is the Slavnov operator...
Aug
26
revised Variational derivatives of strongly connected diagrams functional in gauge theory
Re-formatted quite a bit (the whole thing); improved TeX
Aug
26
suggested suggested edit on Variational derivatives of strongly connected diagrams functional in gauge theory
Aug
20
comment Tricks for Computing Riemann Curvature Tensor with Levi-Civita connection
If you know about differential forms, you may want to consider computing the curvature 2-form (far easier when the metric is diagonal and you can easily guess the tetrad components)...then relate it back to the Riemann tensor...
Aug
19
revised Wick Rotation in Curved space
added 1532 characters in body