Skip to main content

Timeline for 3N-dimensional integral

Current License: CC BY-SA 3.0

20 events
when toggle format what by license comment
May 17, 2020 at 18:27 answer added chris timeline score: 1
Jun 25, 2019 at 2:28 answer added Carl Woll timeline score: 6
Mar 19, 2013 at 4:30 answer added Jens timeline score: 12
Feb 21, 2013 at 4:32 comment added acl @LeonidShifrin good advice then, it should be described clearly there.
Feb 20, 2013 at 2:33 comment added Leonid Shifrin @acl Also, when I referred to the dimensional regularization, I only meant that many textbooks which cover it describe the generalized spherical coordinates in some detail. I did not mean to suggest actually using the regularization, since the integral is convergent.
Feb 20, 2013 at 2:33 answer added whuber timeline score: 12
Feb 20, 2013 at 2:31 comment added acl @LeonidShifrin right sorry, I somehow missed your second clarification (and yes I've also done far too many such integrals and didn't like them...)
Feb 20, 2013 at 2:28 comment added Leonid Shifrin @acl I agree, I made a note on that myself, right below my first suggestion. I think this was just a reflex - I've done too many of those diagrams with dimensional regularization at the time (actually, I personally dislike it, because it is unphysical and regularizes both UV and IR, which is rather non-sensical given that UV and IR phenomena are often utterly different, except possibly for the case of anomalies. I prefer Pauli-Villars). But that's all in the past, now I am just a programmer, one of many.
Feb 20, 2013 at 2:20 comment added acl @LeonidShifrin I'm fairly sure dimensional reguralization isn't necessary for multidimensional gaussian integrals :) It factorizes, also, you can go to generalized spherical coordinates. However this seems to really be asking "how do I set up multidimensional integrals". In any case I think the real answer is "you're better off with some sort of monte carlo scheme for large N and arbitrary integrands"
Feb 20, 2013 at 0:09 history reopened whuber
Mr.Wizard
Feb 19, 2013 at 20:45 review Reopen votes
Feb 20, 2013 at 0:11
Feb 19, 2013 at 20:26 comment added whuber I have voted to reopen because I believe there is a legitimate interpretation of the question, as suggested by my edit of it (and I recall seeing similar issues raised on this site but do not recall seeing a general answer).
Feb 19, 2013 at 20:19 history edited whuber CC BY-SA 3.0
added 159 characters in body; edited tags
Feb 18, 2013 at 16:29 history closed Ajasja
Dr. belisarius
rcollyer
Yves Klett
Vitaliy Kaurov
not a real question
Feb 18, 2013 at 16:17 review Close votes
S Feb 18, 2013 at 16:32
Feb 18, 2013 at 16:12 review First posts
S Feb 18, 2013 at 16:32
Feb 18, 2013 at 16:11 comment added Leonid Shifrin Actually, in this case, it is even much simpler, your integral factorizes into a product of simple integrals.
Feb 18, 2013 at 16:04 comment added Leonid Shifrin You don't need Mathematica to compute this. Switch to the generalized spherical coordinates and integrate over r and the angles. This is exmplained in many texts on Quantum Field Theory, look up dimensional regularization.
Feb 18, 2013 at 15:59 comment added Szabolcs Integrate only supports integrating with respect to scalar variables, i.e. you need to integrate by the components of the vector. See the doc page on Integrate on how, and pay attention to spelling of names and capitalisation. (Integrate, E^x, and don't use N as a variable because it's a built-in symbol)
Feb 18, 2013 at 15:52 history asked user5966 CC BY-SA 3.0