53 research outputs found
High energy protons from PKS 1333-33
In this letter we give an account of the possible acceleration of protons in
the outer radio lobes of the active galaxy PKS 1333-33. We also make estimates
of the arrival energy spectrum.Comment: 3 pages revtex, two figures, to appear in Mod. Phys. Lett.
Variable rest masses in 5-dimensional gravitation confronted with experimental data
Cosmological solutions of Einstein equation for a \mbox{5-dimensional}
space-time, in the case of a dust-filled universe, are presented. With these
solutions we are able to test a hypothetical relation between the rest mass of
a particle and the dimension. Comparison with experiment strongly
refutes the implied dependence of the rest mass on the cosmological time.Comment: Some references adde
Beyond Analog Gravity: The Case of Exceptional Dynamics
We show that it is possible to go beyond the simple kinematical aspects of
the analog models of gravity. We exhibit the form of the Lagrangian that
describes the dynamics of a self-interacting field as an interaction
between and its associated effective metric In
other words the non-linear equation of motion of the field may be interpreted
as the gravitational influence on by its own effective metric which,
in our scheme becomes an active partner of the dynamics of Comment: This new version is an extended version of the previous one. All
previous results are mantaine
Cosmological Effects of Nonlinear Electrodynamics
It will be shown that a given realization of nonlinear electrodynamics, used
as source of Einstein's equations, generates a cosmological model with
interesting features, namely a phase of current cosmic acceleration, and the
absence of an initial singularity, thus pointing to a way to solve two
important problems in cosmology
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