arXiv subjects
Publications and source records attributed to T R Govindarajan.
Stueckelberg introduced an axion like scalar field to provide mass to the gauge electromagnetic field without breaking gauge invariance. This can be considered as a precursor to the spontaneously broken abelian Higgs model. We will consider its role in cosmology to provide a novel candidate to the dark matter question. In addition its implications to deeper issues will be pointed out.
A novel proposal is made to account for the dark matter component of the Universe. Ultralight dark matter with mass $\leq {\cal{O}}(10^{-22})~eV$ is one of the strong candidates for the missing mass which aids the formation of galaxies as well as holding them together. They are also known as fuzzy dark matter(FDM) which will come under Cold Dark matter. The question is what is this particle and its implications. How do we experimentally see it is an outstanding question. We propose to answer some of these questions with some evidences and the estimates.
A novel proposal linking the origin of supermassive blackhole formation and ultralight dark matter. Ultralight bosons of mass $10^{-22}-10^{-24}$ eV which is one of the front running proposal for dark matter could also linked with the formation and evolution of supermassive blackholes at the center of all the galaxies.
Quantum theory on manifolds with boundaries have been studied extensively through von Neumann analysis of self adjoint operators. We approach the issues through introduction of singular $δ$ and $δ'$ potentials. The advantages of this are pointed out as a model for black hole and in several other examples.
We study phase structures of quantum field theories in fuzzy geometries. Several examples of fuzzy geometries as well as QFT's on such geometries are considered. They are fuzzy spheres and beyond as well as noncommutative deformations of BTZ blackholes. Analysis is done analytically and through simulations. Several features like novel stripe phases as well as spontaneous symmetry breaking avoiding Colemen, Mermin, Wagner theorem are brought out. Also we establish that these phases are stable due to topological obstructions.
After briefly reviewing the gauge symmetry in Moyal spacetimes, we analyse aspects of symmetry breaking within a quantisation program preserving the twisted Poincaré symmetry. We develop the LSZ approach for Moyal spacetimes and derive a mapping for scattering amplitudes on these spacetimes from the corresponding ones on the commutative spacetime. This map applies in the presence of spontaneous breakdown of symmetries as well. We also derive Goldstone's theorem on Moyal spacetime. The formalism developed here can be directly applied to the twisted standard model.
The study of BTZ blackhole physics and the cosmological horizon of 3D de Sitter spaces are carried out in unified way using the connections to the Chern Simons theory on three manifolds with boundary. The relations to CFT on the boundary is exploited to construct exact partition functions and obtain logarithmic corrections to Bekenstein formula in the asymptotic regime. Comments are made on the dS/CFT correspondence frising from these studies.
The existence of ring-like and knotted solitons in O(3) non-linear sigma model is analysed. The role of isotopy of knots/links in classifying such solitons is pointed out. Appearance of torus knot solitons is seen.