2006/06/30 by Jogesh C. Pati, JOGESH C. PATI
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Noncommutative and Quantum Gravity Theories #hep-ph #hep-th
paper · pdf · doi:10.1142/s0218271806009030
published as Int.J.Mod.Phys.D15:1677-1698,2006 · A chart showing some insights gained in the world of the very small and that of the very large is included. A few relevant references are added. Some clarification is made in the last section as regards the question of understanding versus landscape and anthropism
arxiv created 2006/08/16 · openalex publication_date 2006/10/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
In the first part of this paper, we explain what empirical evidence points to the need for having an effective grand unification-like symmetry possessing the symmetry SU(4)-color in 4D. If one assumes the premises of a future predictive theory including gravity — be it string/M-theory or a reincarnation — this evidence then suggests that such a theory should lead to an effective grand unification-like symmetry as above in 4D, near the string-GUT-scale, rather than the standard model symmetry. Advantages of an effective supersymmetric G (224) = SU (2) L × SU (2) R × SU (4) c or SO(10) symmetry in 4D in explaining (i) observed neutrino oscillations, (ii) baryogenesis via leptogenesis, and (iii) certain fermion mass-relations are noted. And certain distinguishing tests of a SUSY G(224) or SO(10)-framework involving CP and flavor violations (as in μ → eγ, τ → μγ, edm's of the neutron and the electron) as well as proton decay are briefly mentioned. Recalling some of the successes we have had in our understanding of nature so far, and the current difficulties of string/M-theory as regards the large multiplicity of string vacua, some comments are made on the traditional goal of understanding vis a vis the recently evolved view of landscape and anthropism.