Talk detail

Participant	Bhattacharjee, Srijit
Institution	Saha Institute Of Nuclear Physics - 1/AF Bidhannagar - Kolkata - West Bengal - India

Session	QG2	Accepted	No	Order	5	Time		20'
Talk	Oral abstract	Title	Infrared Instability in Graviton Higgs Theory
Co-authors	Parthasarathi Majumdar
Abstract	We investigate the one-loop infrared behaviour of the effective potential in minimally coupled graviton Higgs theory in Minkowski background. The gravitational analogue of one loop Coleman Weinberg effective potential turns out to be complex, the imaginary part indicating an infrared instability. This instability is traced to a tachyonic pole in the graviton propagator for constant Higgs fields. Physical implications of this behaviour are studied. We also discuss physical differences between gauge theories coupled to Higgs fields and graviton Higgs theory.

Session	GT5	Accepted	Yes	Order	8	Time	15.45-16.00	15'
Talk	Oral abstract	Title	Infrared Instability in Graviton Higgs Theory
Co-authors	Parthasarathi Majumdar
Abstract	We investigate the one-loop infrared behaviour of the effective potential in minimally coupled graviton Higgs theory in Minkowski background. The gravitational analogue of one loop Coleman Weinberg effective potential turns out to be complex, the imaginary part indicating an infrared instability. This instability is traced to a tachyonic pole in the graviton propagator for constant Higgs fields. Physical implications of this behaviour are studied. We also discuss physical differences between gauge theories coupled to Higgs fields and graviton Higgs theory.

Session	GT5	Accepted	Yes	Order	992	Time
Talk	Poster abstract	Title	Vilkovisky-DeWitt Coleman-Weinberg potential revisited in "gauge-free" approach
Co-authors
Abstract	An alternative approach to scalar quantum electrodynamics has been proposed where the usual gauge redundancy of the theory do not manifest. The gauge-dependence of Coleman- Weinberg effective potential is resolved using gauge-free approach leading to a unique scalar to vector mass ratio. We compare our result with the one obtained in Vilkovisky-DeWitt’s geometric framework and it is shown that it differs from the standard result reported earlier. We also discuss possible modifications of the Coleman-Weinberg potential if we adopt the Vilkovisky-DeWitt’s method in the gauge-free scalar QED.

Session	AT4	Accepted	Yes	Order	997	Time
Talk	Poster abstract	Title	Guge invariant couplings to torsion: a string inspired model
Co-authors	Ayan Chatterjee
Abstract	In a consistent heterotic string theory, the Kalb-Ramond field, which is the source of spacetime torsion, is augmented by Yang-Mills and gravitational Chern-Simons terms. When compactified to 4-dimensions and in the field theory limit, such additional terms give rise to interactions with interesting astrophysical predictions like rotation of plane of polarization for electromagnetic and gravitational waves. On the other hand, if one is also interested in coupling 2 or 3-form (Abelian or non-Abelian) gauge fields to torsion, one needs another class of interaction. In this paper, we shall study this interaction and offer some astrophysical and cosmological predictions.