MG13 - Talk detail |
Participant |
Bhattacharjee, Srijit | |||||||
Institution |
Saha Institute Of Nuclear Physics - 1/AF Bidhannagar - Kolkata - West Bengal - India | |||||||
Session |
QG2 |
Accepted |
|
Order |
Time |
|||
Talk |
Oral abstract |
Title |
Infrared Instability in Graviton Higgs Theory | |||||
Co-authors | ||||||||
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 |
|
Order |
Time |
|||
Talk |
Oral abstract |
Title |
Infrared Instability in Graviton Higgs Theory | |||||
Co-authors | ||||||||
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 |
|
Order |
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-DeWitts 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-DeWitts method in the gauge-free scalar QED. |
|||||||
Session |
AT4 |
Accepted |
|
Order |
Time |
|||
Talk |
Poster abstract |
Title |
Guge invariant couplings to torsion: a string inspired model | |||||
Co-authors | ||||||||
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. |
|||||||