43 research outputs found
Conformally Coupled Induced Gravity with Gradient Torsion
It is found that conformally coupled induced gravity with gradient torsion
gives a dilaton gravity in Riemann geometry. In the Einstein frame of the
dilaton gravity the conformal symmetry is hidden and a non-vanishing
cosmological constant is not plausible due to the constraint of the conformal
coupling.Comment: 8pages, LaTeX, no figure, to be appeared in PR
Asymptotic Conformal Invariance of SU(2) and Standard Models in Curved Space-time
The asymptotic conformal invariance of some SU(2) model and Standard Model in
curved space-time are investigated. We have examined the conditions for
asymptotic conformal invariance for these models numerically.Comment: 13 pages, Revtex3.
Fermion Production in Strong Magnetic Field and its Astrophysical Implications
We calculate the effective potential of a strong magnetic field induced by
fermions with anomalous magnetic moments which couple to the electromagnetic
field in the form of the Pauli interaction. For a uniform magnetic field, we
find the explicit form of the effective potential. It is found that the
non-vanishing imaginary part develops for a magnetic field stronger than a
critical field and has a quartic form which is quite different from the
exponential form of the Schwinger process. We also consider a linear magnetic
field configuration as an example of inhomogeneous magnetic fields. We find
that the imaginary part of the effective potential is nonzero even below the
critical field and shows an exponentially decreasing behavior with respect to
the inverse of the magnetic field gradient, which is the non-perturbative
characteristics analogous to the Schwinger process. These results imply the
instability of the strong magnetic field to produce fermion pairs as a purely
magnetic effect. The possible applications to the astrophysical phenomena with
strong magnetic field are also discussed.Comment: 13 pages, 3 figure
Production of Neutral Fermion in Linear Magnetic Field through Pauli Interaction
We calculate the production rate of neutral fermions in linear magnetic
fields through the Pauli interaction. It is found that the production rate is
exponentially decreasing function with respect to the inverse of the magnetic
field gradient, which shows the non-perturbative characteristics analogous to
the Schwinger process. It turns out that the production rate density depends on
both the gradient and the strength of magnetic fields in 3+1 dimension. It is
quite different from the result in 2+1 dimension, where the production rate
depends only on the gradient of the magnetic fields, not on the strength of the
magnetic fields. It is also found that the production of neutral fermions
through the Pauli interaction is a magnetic effect whereas the production of
charged particles through minimal coupling is an electric effect.Comment: 11 pages, 2 figure