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Related papers: Unparticles: Interpretation and Cosmology

200 papers

Unimodular gravity addresses the old cosmological constant (CC) problem, explaining why such constant is not at least as large as the largest particle mass scale, but classically it is indistinguishable from ordinary gravity. Conversely,…

High Energy Physics - Theory · Physics 2024-08-05 Alberto Salvio

The cosmological constant is an unexplained until now phenomena of nature that requires an explanation through string effects. The apparent discrepancy between theory and experiment is enourmous and has already been explained several times…

General Physics · Physics 2007-05-23 Gordon Chalmers

A canonical particle definition via the diagonalisation of the Hamiltonian for a quantum field theory in specific curved space-times is presented. Within the provided approach radial ingoing or outgoing Minkowski particles do not exist. An…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Ralf Schützhold

Within the so-called scaled quantum theory, the standard bouncing ball problem is analyzed under the presence of a gravitational field and harmonic potential. In this framework, the quantum-classical transition of the density matrix is…

Quantum Physics · Physics 2024-10-25 S. V. Mousavi , S. Miret-Artés

In two spatial dimensions, spin characterizes how particle states re-phase under changes of frame that leave their momentum and energy invariant. Massless particles can in principle have non-trivial spin in this sense, but all existing…

High Energy Physics - Theory · Physics 2015-06-19 Philip Schuster , Natalia Toro

Low energy phenomenology of the unparticle physics associated with an exact scale invariant sector possessing a non-trivial infrared fixed point at a higher energy scale is explored for both electron-positron and hadronic colliders. Feynman…

High Energy Physics - Phenomenology · Physics 2008-11-26 Kingman Cheung , Wai-Yee Keung , Tzu-Chiang Yuan

We want to establish the basic properties of a scale invariant cosmology, that also accounts for the hypothesis of scale invariance of the empty space at large scales. We write the basic analytical properties of the scale invariant…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Andre Maeder

We review a cosmology in which particles are fluctuationally created from a background Zero Point Field. This cosmology is consistent with recent observations of an ever expanding and accelerating universe, as also the recently confirmed…

General Physics · Physics 2015-06-26 B. G. Sidharth

The state of our understanding of cosmology is reviewed from an astrophysical cosmologist point of view with a particular emphasis given to recent observations and their impact. Discussion is then presented on the implications for particle…

High Energy Physics - Phenomenology · Physics 2007-05-23 Masataka Fukugita

A conjecture on the origin of elementary particle masses is discussed, based on the micro-universe and quantum state reduction concepts. The reduction of the quantum state of a real particle is understood to take place objectively; in every…

General Physics · Physics 2009-05-26 L. Chiatti

It is shown that the theory of dark matter can be derived from the first principles. Particles representing a new form of matter gravitate but do not interact electromagnetically, strongly and weakly with the known elementary particles.…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ivanhoe Pestov

We consider the standard model with local scale invariance. The theory shows exact scale invariance of dimensionally regulated action. We show that massless gauge fields, which may be abelian or non-abelian, lead to vanishing contribution…

High Energy Physics - Phenomenology · Physics 2010-08-19 Pavan K. Aluri , Pankaj Jain , Subhadip Mitra , Sukanta Panda , Naveen K. Singh

We demonstrate, by giving a specific example, that supersymmetry can be left unbroken without running into conflict with observation. The key idea is to employ a discrete form of supersymmetry. Amongst other interesting features, this…

High Energy Physics - Phenomenology · Physics 2015-03-17 Gerhart Seidl

A conserved cosmological perturbation is associated with each quantity whose local evolution is determined entirely by the local expansion of the Universe. It may be defined as the appropriately normalised perturbation of the quantity,…

Astrophysics · Physics 2008-11-26 David H Lyth , David Wands

One hope to solve the cosmological constant problem is to identify a symmetry principle, based on which the cosmological constant can be reduced either to zero, or to a tiny value. Here, we note that requiring that the vacuum state is…

General Relativity and Quantum Cosmology · Physics 2011-06-01 Jurjen F. Koksma , Tomislav Prokopec

Theoretical developments related to the gravitational interaction have questioned the notion of particle in quantum field theory (QFT). For instance, uniquely-defined particle states do not exist in general, in QFT on a curved spacetime.…

General Relativity and Quantum Cosmology · Physics 2013-05-07 Daniele Colosi , Carlo Rovelli

In an undulant universe, cosmic expansion is characterized by alternating periods of acceleration and deceleration. We examine cosmologies in which the dark-energy equation of state varies periodically with the number of e-foldings of the…

Astrophysics · Physics 2009-11-11 Gabriela Barenboim , Olga Mena Requejo , Chris Quigg

We provide a review on the physics associated with phase transitions in which continuous scale invariance is broken into discrete scale invariance. The rich features of this transition characterized by the abrupt formation of a geometric…

Mesoscale and Nanoscale Physics · Physics 2021-04-15 Omrie Ovdat , Eric Akkermans

In contemporary particle physics, the masses of fundamental particles are incalculable constants, being supplied by experimental values. Inspired by observation of the empirical particle mass spectrum, and their corresponding physical…

General Physics · Physics 2014-02-28 Johan Hansson

The concepts of Lorentz invariance of local (flat space) physics, and unitarity of time evolution and the S-matrix, are famously rigid and robust, admitting no obvious consistent theoretical deformations, and confirmed to incredible…

High Energy Physics - Theory · Physics 2018-11-06 Nima Arkani-Hamed , Paolo Benincasa