Talk:Young tableau

Untitled
Regards to all Foice (talk) 12:37, 25 December 2007 (UTC)


 * Serious terminological and expository issues aside, how about at least correcting the grammar? Many sentences just don't fit together. Surely you can write better than this! Arcfrk (talk) 08:00, 18 January 2008 (UTC)


 * I agree. While giving examples is useful, it should at least be clear what these are examples of. What is written under the title "Multiplication Rule of Tableaux" seems to be a formulation of the Littlewood-Richardson rule (using the rather vague original language of the 1930's), but neither the description nor the example is correct (in the example there should not be two 'a's in the same column, and besides the product should decompose as s(1,1)*s(2,1)=s(3,2)+s(3,1,1)+s(2,2,1)+s(2,1,1,1), possibly replacing the last term by s(1) if N=4, (cf. http://young.sp2mi.univ-poitiers.fr/cgi-bin/form-prep/marc/LiE_form.act?action=LRR ).


 * Furthermore I don't think a Wikipedia article should serve as one author's to-do list.


 * I propose moving the SU(n) stuff to a separate page, or removing it altogether if it cannot be tidied up.Marc van Leeuwen (talk) 13:49, 29 February 2008 (UTC)


 * It cannot be fixed and I've removed it altogether. Littlewood–Richardson rule article would be a proper place to present examples. Arcfrk (talk) 22:24, 29 February 2008 (UTC)

Frankly I think that cutting such a huge part of text is a mistake. I think so, not just because I am author of such a content, but mainly because I see that the page has drifted back to the "mathematics-only" shape I found when I first edited it. This page is quite specialistic, as often happen in math pages I read, thus is not usable to non specialists. I strongly suggest to reintroduce something (here or in other pages) that brings this stuff down to earth. Maybe the content I added is stinky for a mathematician, but I can assure it prove to be very useful to physicist. Before erasing such a long contribution I would think twice, keeping in mind that this page has to reach different audiences. Please discuss with me how to bring this stuff in a page readable to non specialists. Foice (talk) 13:10, 4 April 2008 (UTC)


 * It is disingeneous to claim that there was no consultation: I left you note (see above) asking to fix the grammar, which you ignored for several months. Quality of writing is not synonymous with length. Your intentions may have been good, but the text you had hastily composed was not suitable either for physicists or mathematicians. Among the most immediate issues I can point out nonstandard terminology, lack of logical coherence, and such poor grammar that even for someone familiar with the subject, hardly any meaning could have been discerned. If you really are interested in improving this page, please, indicate your specific concerns about the present version. Arcfrk (talk) 17:37, 4 April 2008 (UTC)

Well, your comment appeared weeks after my contribution, and, since I don't live into the Wiki, I think is normal to not be aware of the discussions going on. Is there anyway, like in forums, to be noticed when something happen in a page you contributed? Then let me say that what I explained is mostly what you find on Georgi's book, which uses the notation and language common to physicists. I agree with you this is not rigorous, maybe, but this is what a physicist understands. To give an idea of where we are (need to be) in this subject let me say that most theorists have Hamermesh book as a reference, this is 1962 and probably let you understand how basic and application-oriented are the things that we need. Thus I claim the page lacks of examples that allows the poor undergraduate student to compute su(n) representation products. he/she usually needs to be able to compute the multiplicity of a given irrep in a product of two irrep (which can be accomplished with the rule you linked using skew tableaux) but also write it explcitily in components like happen in p381 of Hamermesh. Moreover he/she has to be able to compute the dimension with the hook-rule d=F/H i wrote. the well equipped student should also be able to properly decompose a irrep of G into irreps of H contained in G. Typically Su(3) irreps as SU(2)xU(1). (this is something i'm not able to do!) Certainly one has to be able to find (maximal) subgroups, for instance like in the book of Robert Cahn "Semisimple lie algebras and their representations" (free PS from the author page). This should make clear what is needed and what's the level of the discussion that the audience is supposed to understand. Maybe you understand also the need for such explicit pictures.

As far as concern grammar, well, this is wiki, you find a mistake, you can correct it. :) BTW I'll more careful in the future

213.140.16.184 (talk) 14:43, 7 April 2008 (UTC)

representation-tableau correspondence lacking
A good 1/3 of the body of this article talks about content relating to the correspondence between a young tableau and a rep of S_n. But it never talks about what the correspondence is, making a good deal of the body of this article pretty hollow! — Preceding unsigned comment added by 2607:F140:400:A002:9284:DFF:FEF3:FFE5 (talk) 00:50, 22 February 2014 (UTC)