scholarly journals Torsion-gravity for Dirac fields and their effective phenomenology

2014 ◽  
Vol 29 (26) ◽  
pp. 1450133 ◽  
Author(s):  
Luca Fabbri
Keyword(s):  
New Physics ◽  
Nonlinear Interactions ◽  
Dirac Fields ◽  
Relativistic Approximation ◽  
Fermion Fields ◽  
Matter Fields ◽  
Dirac Matter

We will consider the torsional completion of gravity for a background filled with Dirac matter fields, studying the weak-gravitational non-relativistic approximation, in view of an assessment about their effective phenomenology: we discuss how the torsionally-induced nonlinear interactions among fermion fields in this limit are compatible with all experiments and remarks on the role of torsion to suggest new physics are given.

scholarly journals WEAKLY-INTERACTING MASSIVE PARTICLES IN TORSIONALLY-GRAVITATING DIRAC THEORY

2013 ◽  
Vol 22 (10) ◽  
pp. 1350071 ◽  
Author(s):  
LUCA FABBRI
Keyword(s):  
Dark Matter ◽  
Weakly Interacting Massive Particles ◽  
Dirac Theory ◽  
Dirac Fields ◽  
Weakly Interacting ◽  
Massive Particles ◽  
Matter Fields ◽  
Dirac Matter

We shall consider the problem of Dark Matter (DM) in torsion gravity with Dirac matter fields; we will consider the fact that if Weakly-Interacting Massive Particles in a bath are allowed to form condensates then torsional effects may be relevant even at galactic scales: we show that torsionally-gravitating Dirac fields have interesting properties for the problem of DM. We discuss consequences.

scholarly journals A torsional completion of gravity for Dirac matter fields and its applications to neutrino oscillations

2016 ◽  
Vol 31 (03) ◽  
pp. 1650014
Author(s):  
Luca Fabbri ◽  
Stefano Vignolo
Keyword(s):  
Neutrino Oscillations ◽  
Dirac Fields ◽  
Matter Fields ◽  
Dirac Matter

In this paper, we consider the torsional completion of gravitation for an underlying background filled with Dirac fields, applying it to the problem of neutrino oscillations: we discuss the effects of the induced torsional interactions as corrections to the neutrino oscillations mechanism.

scholarly journals Study of Rare Mesonic Decays Involving Di-Neutrinos in Their Final State

2018 ◽  
Vol 2018 ◽  
pp. 1-20
Author(s):  
Azeem Mir ◽  
Farida Tahir ◽  
Shakeel Mahmood ◽  
Shi- Hai Dong
Keyword(s):  
Branching Fractions ◽  
New Physics ◽  
Supersymmetric Model ◽  
Final State ◽  
Yukawa Couplings ◽  
Leptonic Decays ◽  
Pseudoscalar Mesons ◽  
Theoretical Predictions ◽  
Minimal Supersymmetric Model

We have studied phenomenological implication of R-parity violating (Rp) Minimal Supersymmetric Model (MSSM) via analyses of pure leptonic (M→νν¯) and semileptonic decays of pseudoscalar mesons (M→Xνν¯). These analyses involve comparison between theoretical predictions made by Rp MSSM and the Standard Model (SM) with the experimental results like branching fractions (Br) of the said process. We have found, in general, that Rp contribution dominates over the SM contribution, i.e., by a factor of 10 for the pure leptonic decays of KL,S and by 102 and 104 in case of Bs and Bd, respectively. Furthermore, the limits obtained on Rp Yukawa couplings (λαkβ′λαkγ′⁎) by using Br  (M→Xνν¯) are used to calculate Br  (M→νν¯). This demonstrates the role of Rp MSSM as a viable model for the study of new physics contribution in rare decays at places like Super B factories, KOTO (J-PARC) and NA62 at CERN.

Role of gravity in particle physics: A unified approach

2020 ◽  
Vol 29 (11) ◽  
pp. 2041012
Author(s):  
Pedro D. Alvarez ◽  
Mauricio Valenzuela ◽  
Jorge Zanelli
Keyword(s):  
General Relativity ◽  
Standard Model ◽  
Particle Physics ◽  
Laws Of Nature ◽  
Lorentz Transformations ◽  
Unified Approach ◽  
The Standard Model ◽  
Matter Fields

General Relativity (GR) and the Standard Model (SM) of particle physics are two enormously successful frameworks for our understanding the fundamental laws of nature. However, these theoretical schemes are widely disconnected, logically independent and unrelated in scope. Yet, GR and SM at some point must intersect, producing claims about phenomena that should be reconciled. Be it as it may, both schemes share a common basic ground: symmetry under local Lorentz transformations. Here, we will focus on the consequences of assuming this feature from the beginning to combine geometry, matter fields and gauge interactions. We give a rough description of how this could be instrumental for the construction of a unified scheme of gravitation and particle physics.

scholarly journals Gravitational waves and perspectives for quantum gravity

2014 ◽  
Vol 29 (30) ◽  
pp. 1430034 ◽  
Author(s):  
Ilya L. Shapiro ◽  
Ana M. Pelinson ◽  
Filipe de O. Salles
Keyword(s):  
Quantum Gravity ◽  
Gravitational Waves ◽  
Classical Solutions ◽  
Quantum Level ◽  
Quantum Matter ◽  
Higher Derivatives ◽  
Fourth Derivative ◽  
Matter Fields ◽  
Classical Background

Understanding the role of higher derivatives is probably one of the most relevant questions in quantum gravity theory. Already at the semiclassical level, when gravity is a classical background for quantum matter fields, the action of gravity should include fourth derivative terms to provide renormalizability in the vacuum sector. The same situation holds in the quantum theory of metric. At the same time, including the fourth derivative terms means the presence of massive ghosts, which are gauge-independent massive states with negative kinetic energy. At both classical and quantum level such ghosts violate stability and hence the theory becomes inconsistent. Several approaches to solve this contradiction were invented and we are proposing one more, which looks simpler than those what were considered before. We explore the dynamics of the gravitational waves on the background of classical solutions and give certain arguments that massive ghosts produce instability only when they are present as physical particles. At least on the cosmological background one can observe that if the initial frequency of the metric perturbations is much smaller than the mass of the ghost, no instabilities are present.

scholarly journals FERMION DYNAMICS BY INTERNAL AND SPACETIME SYMMETRIES

2009 ◽  
Vol 24 (06) ◽  
pp. 415-427 ◽  
Author(s):  
NAKIA CARLEVARO ◽  
ORCHIDEA MARIA LECIAN ◽  
GIOVANNI MONTANI
Keyword(s):  
Gauge Theory ◽  
Stationary Solutions ◽  
Gauge Fields ◽  
Spacetime Symmetries ◽  
Lorentz Transformations ◽  
Relativistic Limit ◽  
Spinor Structure ◽  
Flat Spacetime ◽  
Fermion Fields

This paper is devoted to introduce a gauge theory of the Lorentz group based on the ambiguity emerging in dealing with isometric diffeomorphism-induced Lorentz transformations. The behaviors under local transformations of fermion fields and spin connections (assumed to be ordinary world vectors) are analyzed in flat spacetime and the role of the torsion field, within the generalization to curved spacetime, is briefly discussed. The fermion dynamics is then analyzed including the new gauge fields and assuming time-gauge. Stationary solutions of the problem are also analyzed in the non-relativistic limit, to study the spinor structure of an hydrogen-like atom.

scholarly journals Turing's theory of morphogenesis of 1952 and the subsequent discovery of the crucial role of local self-enhancement and long-range inhibition

2012 ◽  
Vol 2 (4) ◽  
pp. 407-416 ◽  
Author(s):  
Hans Meinhardt
Keyword(s):  
Pattern Formation ◽  
De Novo ◽  
Molecular Genetic ◽  
Stable State ◽  
Nonlinear Interactions ◽  
Alan Turing ◽  
Component Systems ◽  
Genetic Level ◽  
Reaction Schemes

In his pioneering work, Alan Turing showed that de novo pattern formation is possible if two substances interact that differ in their diffusion range. Since then, we have shown that pattern formation is possible if, and only if, a self-enhancing reaction is coupled with an antagonistic process of longer range. Knowing this crucial condition has enabled us to include nonlinear interactions, which are required to design molecularly realistic interactions. Different reaction schemes and their relation to Turing's proposal are discussed and compared with more recent observations on the molecular–genetic level. The antagonistic reaction may be accomplished by an inhibitor that is produced in the activated region or by a depletion of a component that is used up during the self-enhancing reaction. The autocatalysis may be realized by an inhibition of an inhibition. Activating molecules can be processed into molecules that have an inhibiting function; patterning of the Wnt pathway is proposed to depend on such a mechanism. Three-component systems, as discussed in Turing's paper, are shown to play a major role in the generation of highly dynamic patterns that never reach a stable state.

ON THE RELATION BETWEEN INDUCED QUANTUM GRAVITY AND JACKIW-TEITELBOIM GRAVITY IN TWO DIMENSIONS

1992 ◽  
Vol 07 (38) ◽  
pp. 3553-3559
Author(s):  
THILO BERGER
Keyword(s):  
Quantum Gravity ◽  
Two Dimensions ◽  
Gravitational Action ◽  
Invariant Formulation ◽  
Gauge Fixing ◽  
Conformal Gauge ◽  
Matter Fields

Jackiw-Teitelboim gravity in the presence of matter fields is studied by using the conformal gauge. It is shown to be equivalent to induced Polyakov gravity in a Weyl invariant formulation. The gravitational action for the vacuum plays the role of a gauge fixing term.

A review of the central role of nonlinear interactions in wind—wave evolution

1993 ◽  
Vol 342 (1666) ◽  
pp. 505-524 ◽  
Keyword(s):  
Surface Waves ◽  
Nonlinear Wave ◽  
High Frequency ◽  
Numerical Experiments ◽  
Wind Wave ◽  
Nonlinear Interactions ◽  
Wave Interactions ◽  
Detailed Review ◽  
Local Perturbations

Nonlinear wave-wave interactions play a central role in the development of wind-generated surface waves. A detailed review of com putational techniques which have been proposed for their evaluation is provided. Numerical experiments are used to determine the manner in which the nonlinear terms control spectral development with fetch, the directional spread of the spectrum and the high-frequency spectral tail. In addition, the nonlinear terms have a shape-stabilizing role, continually smoothing local perturbations in the spectrum and forcing it back to a ‘preferred’ shape.

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