# Etiqueta: string theory

• ## Families from USp(32)

The same trick to descent to three generations can be done starting from the 495 of Sp(32). We are on it, as usual, in physicsforums  https://www.physicsforums.com/threads/the-wrong-turn-of-string-theory-our-world-is-susy-at-low-energies.485247/page-13#post-5913658 As noted there, we still lack of a variant showing the L-R chirality of the SM.  I wonder if we could use some exotic models from E6 or E8…

• ## wrong turns

Woit (What the Hell is Going On?) and Motl (wrong-turn-basins-gut-critics) have sparked a new round of the discussion on the existence, or not, of a wrong turn in the development of theoretical particle physics. The excuse this time is some comments of Nima Arkani-Hamed in a couple of recent lectures, but the running joke is…

• ## Families from SO(32)

$latex \begin{array}{llll} 496=\\ {\bf (1,24,1^c) }&+{\bf [1,15,\bar 3^c]}&+{\bf [1, \bar {15}, 3^c]}&+\\ 1,24,8^c&+[1,10,\bar 6^c]&+[1,\bar {10},6^c]&+\\ (1,1,8^c)&&&+\\&(2,5,3^c)&+(2,\bar 5,\bar 3^c)&+\\ &(1,1,1^c)&+[1,1,1^c]\\ \end{array}$ (or from SO(30), or perhaps just O(10)xU(3) or U(5)xU(3)) Point is, the first three lines seem to contain three generations with electric and colour charge. It is possible to break the 24 and 15…

• ## «No room for self-referring vague half-elementary, half-composite particles»

Comment to a post from Lubos in his blog. Copy paste for reference. http://motls.blogspot.com.es/2017/02/revival-of-bootstrap.html#comment-3171556156 As here you could be stressing the criticism of a comment ten years ago, allow me just a reminder for the people who was not here at that time. We set V as a five, (u,d,s,c,b), of SU(5). Then we go…

• ## bootstraping a space from its tensor square

Consider the tensor square r?r of an irreducible group representation r with itself, and decompose it as irreducible representations. What can we said about the circumstance of finding the initial representation in the list? Or perhaps about finding its conjugate, as for instance in E6: 27?27=351?(27¯?351¯) What groups have representations having this «bootstraping»? Can the…