1,325 reputation
1611
bio website code.google.com/p/notebk
location Los Angeles, CA
age
visits member for 2 years, 3 months
seen 5 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.


1d
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.
1d
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...
1d
revised Variational derivatives of strongly connected diagrams functional in gauge theory
Re-formatted quite a bit (the whole thing); improved TeX
1d
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
Aug
19
answered Wick Rotation in Curved space
Aug
8
revised Lippmann-Schwinger solution
Cleaned up the TeX a little...
Aug
8
suggested suggested edit on Lippmann-Schwinger solution
Aug
6
revised Is it true that the Schrödinger equation only applies to spin-1/2 particles?
added 88 characters in body
Aug
6
answered Is it true that the Schrödinger equation only applies to spin-1/2 particles?
Jul
30
comment Classical Rutherford scattering (partial) derivation
The full text for Rutherford's article is available online, too.
Jul
26
comment How to calculate the 2-point function of gravitons?
Isn't this covered in Feynman's lectures on gravitation?
Jul
26
revised Yang Mills theory and SU(N) groups
Fixed a few typos
Jul
26
suggested suggested edit on Yang Mills theory and SU(N) groups
Jul
25
comment Lorentz group representations in QFT: what's the vector space?
@joshphysics I always love your posts since you contribute great content. But I think you might be a little sloppy here: what you call "$\mathrm{Lin}(V)$" is not exactly the codomain for a group representation (it should be $\mathrm{GL}(V)$ -- the set of all invertible linear operators on $V$). Just a minor detail...
Jul
6
comment Is general relativity holonomic?
For the surface deformation algebra, describing the constraints of GR, the answer is "no-ish, GR is not holonomic (in some field theoretic analogous sense)". See Teitelboim's "How the Commutators of Constraints Reflect the Spacetime Structure" Ann. of Phys. 79 (1973) 542--557 doi:10.1016/0003-4916(73)90096-1 for a discussion of the nature of the constraint algebra...
Jul
3
revised A question on an exercise from Gravitation by Misner, Thorne and Wheeler
Fixed the TeX formatting
Jul
3
suggested suggested edit on A question on an exercise from Gravitation by Misner, Thorne and Wheeler
Jun
29
comment Can a curvature in time (and not space) cause acceleration?
Isn't that basically the Newton-Cartan theory of gravity? Keep space flat, but curve the temporal dimension, and you get a geometric description of Newton's theory of gravity. See, e.g., Willie Wong's blogpost or wikipedia.