187 research outputs found
Three Duality Symmetries between Photons and Cosmic String Loops, and Macro and Micro Black Holes
We present a review of two thermal duality symmetries between two different kinds of systems: photons and cosmic string loops, and macro black holes and micro black holes, respectively. It also follows a third joint duality symmetry amongst them through thermal equilibrium and stability between macro black holes and photon gas, and micro black holes and string loop gas, respectively. The possible cosmological consequences of these symmetries are discussed
As time goes by
A rather simple and non-technical exposition of our new approach to {\em
Time, Quantum Physics, Black-Hole dynamics}, and {\em Cosmology}, based on
non-critical string theory, is provided. A new fundamental principle, the {\em
Procrustean Principle}, that catches the essence of our approach is postulated:
the low-energy world is {\em unavoidably} an ``open" system due to the
spontaneous truncation of the {\em delocalized, topological} string modes in
continuous interaction with the low-lying-{\em localized} string modes. The
origin of space-time, the expansion of the Universe, the entropy increase and
accompanied irreversibility of time, as well as the collapse of the
wavefunction are all very neatly tied together. Possible observable
consequences include: quantum relaxation with time of the Universal,
fundamental constants, like the velocity of light and the Planck constant
decreasing towards their asymptotic values, and the cosmological
constant diminishing towards zero; possible violation of {\em CPT}
invariance in the system, possible apparent non-conservation of
angular momentum, and possible loss of quantum coherence in SQUID-type
experiments.Comment: CERN-TH.7260/94, 84 pages Latex (no figures
Magnetic monopoles revisited: Models and searches at colliders and in the Cosmos
In this review, we discuss recent developments in both the theory and the
experimental searches of magnetic monopoles in past, current and future
colliders and in the Cosmos. The theoretical models include, apart from the
standard Grand Unified Theories, extensions of the Standard Model that admit
magnetic monopole solutions with finite energy and masses that can be as light
as a few TeV. Specifically, we discuss, among other scenarios, modified
Cho-Maison monopoles and magnetic monopoles in (string-inspired, higher
derivative) Born-Infeld extensions of the hypercharge sector of the Standard
Model. We also outline the conditions for which effective field theories
describing the interaction of monopoles with photons are valid and can be used
for result interpretation in monopole production at colliders. The experimental
part of the review focuses on, past and present, cosmic and collider searches,
including the latest bounds on monopole masses and magnetic charges by the
ATLAS and MoEDAL experiments at the LHC, as well as prospects for future
searches.Comment: 82 pages, 21 figures, invited review; more references and discussions
added; to appear in International Journal of Modern Physics
Dual Dynamics theory
A theory based on dual dynamics (propagation and confinement) is proposed in a mathematical framework including a redefinition of quantum states, creation and annihilation operators, fermions and bosons distinction but also of colored charges and spins. Particles interactions are found to be either direct (fermion-fermion) or indirect (mediated by bosons), as a consequence of a revisited wave-particle duality. Fundamental interactions as well as elementary particles naturally emerge from the dual driving equations applied to vector potential states. They are qualitatively compared to the content of the Standard Model, evidencing some interesting features such as confinement, hierarchy, and parity violation. Introducing nonlinear coupling terms further allows the appearance of a photon wave function and a " composite graviton field " and is foreseen to produce generations of particles through a self trapping mechanism. In the last part, cosmology is analyzed in the framework of the dual dynamics theory. The non-linearities generate Bose-Einstein condensates leading to black-holes through attracting potentials. Quasars and blazars also emerge with the introduction of " jet-particles " originating from the Legendre function of the second kind. Non-baryonic matter finally shows up in the present theory. It can form " dark " Bose-Einstein condensate creating halos around black-holes. A new definition of the equivalence principle between inertial and gravita-tional masses is proposed allowing anti-particles to have negative gravitational masses without violating the usual test experiments. This renews the concept of anti-gravity, which plays the role of dark-energy in the present theory. Finally the universe time-line is envisioned in the context of the coupled and nonlinear dual equations (propagation and confinement), requiring to revisit the Big-Bang and inflation mechanisms, the latter being attributed to a superluminal expansion, which is allowed by the nonlinear terms
Non-collider searches for stable massive particles
The theoretical motivation for exotic stable massive particles (SMPs) and the
results of SMP searches at non-collider facilities are reviewed. SMPs are
defined such that they would be sufficiently long-lived so as to still exist in
the cosmos either as Big Bang relics or secondary collision products, and
sufficiently massive to be beyond the reach of any conceivable
accelerator-based experiment. The discovery of SMPs would address a number of
important questions in modern physics, such as the origin and composition of
dark matter in the Universe and the unification of the fundamental forces. This
review outlines the scenarios predicting SMPs and the techniques used at
non-collider experiments to look for SMPs, eg in cosmic rays and bound in
matter. The limits so far obtained on the fluxes and matter densities of SMPs
which possess various detection-relevant properties such as electric and
magnetic charge are given
The sounds of the Little and Big Bangs
Studies of heavy ion collisions have discovered that tiny fireballs of new
phase of matter -- quark gluon plasma (QGP) -- undergoes explosion, called the
Little Bang. In spite of its small size, it is not only well described by
hydrodynamics, but even small perturbations on top of the explosion turned to
be well described by hydrodynamical sound modes. The cosmological Big Bang also
went through phase transitions, the QCD and electroweak ones, which are
expected to produce sounds as well. We discuss their subsequent evolution and
hypothetical inverse acoustic cascade, amplifying the amplitude. Ultimately,
collision of two sound waves leads to formation of gravity waves, with the
smallest wavelength. We briefly discuss how those can be detected.Comment: This paper is a short semi-popular review describing some recent
developments in two very different fields, united by some common physics. It
was written for the Universe journa
Epistemology of Experimental Gravity - Scientific Rationality
The evolution of gravitational tests from an epistemological perspective framed in the concept of rational reconstruction of Imre Lakatos, based on his methodology of research programmes.
Unlike other works on the same subject, the evaluated period is very extensive, starting with Newton's natural philosophy and up to the quantum gravity theories of today. In order to explain in a more rational way the complex evolution of the gravity concept of the last century, I propose a natural extension of the methodology of the research programmes of Lakatos that I then use during the paper. I believe that this approach offers a new perspective on how evolved over time the concept of gravity and the methods of testing each theory of gravity, through observations and experiments. I argue, based on the methodology of the research programmes and the studies of scientists and philosophers, that the current theories of quantum gravity are degenerative, due to the lack of experimental evidence over a long period of time and of self-immunization against the possibility of falsification. Moreover, a methodological current is being developed that assigns a secondary, unimportant role to verification through observations and/or experiments. For this reason, it will not be possible to have a complete theory of quantum gravity in its current form, which to include to the limit the general relativity, since physical theories have always been adjusted, during their evolution, based on observational or experimental tests, and verified by the predictions made. Also, contrary to a widespread opinion and current active programs regarding the unification of all the fundamental forces of physics in a single final theory, based on string theory, I argue that this unification is generally unlikely, and it is not possible anyway for a unification to be developed based on current theories of quantum gravity, including string theory. In addition, I support the views of some scientists and philosophers that currently too much resources are being consumed on the idea of developing quantum gravity theories, and in particular string theory, to include general relativity and to unify gravity with other forces, as long as science does not impose such research programs.
DOI: 10.13140/RG.2.2.35350.7072
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