Sorry, I again spent a long time without writing anything here... I hope you are having a happy 2013 in spite of all kinds of "sequestrations" on both sides of the Atlantic.
Here are my two last papers. They will appear in the Proceedings of the ICFP 2012 Conference (Crete, June 2012) to be published by the European Physical Journal Web of Conferences, http://www.epj-conferences.org/ , but can already be found at the following adresses :
HAL (France)
http://hal.archives-ouvertes.fr/hal-00795588
http://hal.archives-ouvertes.fr/docs/00/79/55/88/PDF/PreBBCreteNew.pdf
http://hal.archives-ouvertes.fr/hal-00795562
http://hal.archives-ouvertes.fr/docs/00/79/55/62/PDF/UHECRCreteNew.pdf
or the Mathematical Physics archive (University of Texas)
http://www.ma.utexas.edu/mp_arc-bin/mpa?yn=13-18
http://www.ma.utexas.edu/mp_arc/c/13/13-18.pdf
http://www.ma.utexas.edu/mp_arc-bin/mpa?yn=13-19
http://www.ma.utexas.edu/mp_arc/c/13/13-19.pdf
The abstracts are :
Pre-Big Bang, fundamental Physics and noncyclic cosmologies
Detailed analyses of WMAP and Planck data can have significant
implications for noncyclic pre-Big Bang approaches incorporating a new
fundamental scale beyond the Planck scale and, potentially, new ultimate
constituents of matter with unconventional basic properties as compared
to standard particles. Cosmic-ray experiments at the highest energies
can also yield relevant information. Hopefully, future studies will be
able to deal with alternatives: i) to standard physics for the structure
of the physical vacuum, the nature of space-time, the validity of
quantum field theory and conventional symmetries, the interpretation of
string-like theories...; ii) to standard cosmology concerning the origin
and evolution of our Universe, unconventional solutions to the
cosmological constant problem, the validity of inflationary scenarios,
the need for dark matter and dark energy... Lorentz-like symmetries for
the properties of matter can then be naturally stable space-time
configurations resulting from more general primordial scenarios that
incorporate physics beyond the Planck scale and describe the formation
and evolution of the physical vacuum. A possible answer to the question
of the origin of half-integer spins can be provided by a primordial
spinorial space-time with two complex coordinates instead of the
conventional four real ones, leading to a really new cosmology. We
discuss basic questions and phenomenological topics concerning noncyclic
pre-Big Bang cosmologies and potentially related physics. (Contribution
to the International Conference on New Frontiers in Physics, ICFP 2012,
Kolymbari, Crete, June 10-16 2012)
and
High-energy cosmic rays and tests of basic principles of Physics
With the present understanding of data, the observed flux suppression
for ultra-high energy cosmic rays (UHECR) at energies above 4.10E19 eV
can be a signature of the Greisen-Zatsepin-Kuzmin (GZK) cutoff or be
related to a similar mechanism. But it may also correspond, for
instance, to the maximum energies available at the relevant sources. In
both cases, violations of special relativity modifying cosmic-ray
propagation or acceleration at very high energy can potentially play a
role. Other violations of fundamental principles of standard particle
physics (quantum mechanics, energy and momentum conservation, vacuum
homogeneity and "static" properties, effective space dimensions, quark
confinement...) can also be relevant at these energies. In particular,
UHECR data would in principle allow to set bounds on Lorentz symmetry
violation (LSV) in patterns incorporating a privileged local reference
frame (the "vacuum rest frame", VRF). But the precise analysis is far
from trivial, and other effects can also be present. The effective
parameters can be related to Planck-scale physics, or even to physics
beyond Planck scale, as well as to the dynamics and effective symmetries
of LSV for nucleons, quarks, leptons and the photon. LSV can also be at
the origin of GZK-like effects. In the presence of a VRF, and contrary
to a "grand unification" view, LSV and other violations of standard
principles can modify the internal structure of particles at very high
energy and conventional symmetries may cease to be valid at energies
close to the Planck scale. We present an updated discussion of these
topics, including experimental prospects, new potentialities for
high-energy cosmic ray phenomenology and the possible link with
unconventional pre-Big Bang scenarios, superbradyon (superluminal preon)
patterns... The subject of a possible superluminal propagation of
neutrinos at accelerator energies is also dealt with. (Contribution to
the International Conference on New Frontiers in Physics, ICFP 2012,
Kolymbari, Crete, June 10-16 2012)
(end of the abstracts)
I will comment on these papers in my next article of this blog.
All the best
Luis Gonzalez-Mestres
