2,627 research outputs found
Large-scale magnetic fields from inflation in teleparallel gravity
Generation of large-scale magnetic fields in inflationary cosmology is
studied in teleparallelism, where instead of the scalar curvature in general
relativity, the torsion scalar describes the gravity theory. In particular, we
investigate a coupling of the electromagnetic field to the torsion scalar
during inflation, which leads to the breaking of conformal invariance of the
electromagnetic field. We demonstrate that for a power-law type coupling, the
current magnetic field strength of G on 1 Mpc scale can be
generated, if the backreaction effects and strong coupling problem are not
taken into consideration.Comment: 4 pages, no figure, to be published in the Proceedings of the "12th
Asia Pacific Physics Conference.
Inverse-Chirp Imprint of Gravitational Wave Signals in Scalar Tensor Theory
The scalar tensor theory contains a coupling function connecting the
quantities in the Jordan and Einstein frames, which is constrained to guarantee
a transformation rule between frames. We simulate the supernovae core collapse
with different choices of coupling functions defined over the viable region of
the parameter space and find that a generic inverse-chirp feature of the
gravitational waves in the scalar tensor scenario.Comment: 13 pages, 4 figures, revised version accepted by EPJ
Maximal violation of Clauser-Horne-Shimony-Holt inequality for two qutrits
Bell-Clauser-Horne-Shimony-Holt inequality (in terms of correlation
functions) of two qutrits is studied in detail by employing tritter
measurements. A uniform formula for the maximum value of this inequality for
tritter measurements is obtained. Based on this formula, we show that
non-maximally entangled states violate the Bell-CHSH inequality more strongly
than the maximally entangled one. This result is consistent with what was
obtained by Ac{\'{i}}n {\it et al} [Phys. Rev. A {\bf 65}, 052325 (2002)] using
the Bell-Clauser-Horne inequality (in terms of probabilities).Comment: 6 pages, 3 figure
- …