Dark energy in the universe, the irreversibility of time and neutrinos

Mavromatos, Nikolaos

doi:10.1590/s0103-97332005000200013

“…In particular, they are generated when cosmic rays hit atoms. Current evidences of dark matter and dark energy can be related to the issue that neutrinos have masses and that mass eigenstates mix and/or superimpose [45,410,434]. The observation of such a mixing is related to suitable constraints.…”

Section: An Example: Neutrino Oscillation Phase Dynamically Induced B...mentioning

confidence: 99%

Extended Theories of Gravity

Capozziello,

De Laurentis

2011

Preprint

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Extended Theories of Gravity can be considered a new paradigm to cure shortcomings of General Relativity at infrared and ultraviolet scales. They are an approach that, by preserving the undoubtedly positive results of Einstein's Theory, is aimed to address conceptual and experimental problems recently emerged in Astrophysics, Cosmology and High Energy Physics. In particular, the goal is to encompass, in a self-consistent scheme, problems like Inflation, Dark Energy, Dark Matter, Large Scale Structure and, first of all, to give at least an effective description of Quantum Gravity. We review the basic principles that any gravitational theory has to follow. The geometrical interpretation is discussed in a broad perspective in order to highlight the basic assumptions of General Relativity and its possible extensions in the general framework of gauge theories. Principles of such modifications are presented, focusing on specific classes of theories like f (R)-gravity and scalar-tensor gravity in the metric and Palatini approaches. The special role of torsion is also discussed. The conceptual features of these theories are fully explored and attention is payed to the issues of dynamical and conformal equivalence between them considering also the initial value problem. A number of viability criteria are presented considering the post-Newtonian and the post-Minkowskian limits. In particular, we discuss the problems of neutrino oscillations and gravitational waves in Extended Gravity. Finally, future perspectives of Extended Gravity are considered with possibility to go beyond a trial and error approach.

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“…If we consider Solar neutrinos, we can use the following values: M ∼ M ⊙ ∼ 1.9891 × 10 30 Kg, r A ∼ r ⊕ ∼ 6.3 × 10 3 Km, and r B ∼ r A + D, where D ∼ 1.5 × 10 8 Km is the Sun-Earth distance. In order to estimate the phases differences (7), (8) and (16), we introduce the ratio Q grav defined as…”

mentioning

confidence: 99%

“…In particular, they are generated when cosmic rays hit atoms. Current evidences of dark matter and dark energy can be related to the issue that neutrinos have masses and that mass eigenstates mix and/or superimpose [6][7][8][9]. The observation of such a mixing is related to suitable constraints.…”

mentioning

confidence: 99%

NEUTRINO OSCILLATION PHASE DYNAMICALLY INDUCED BY f(R)-GRAVITY

Capozziello

¹

,

Vernieri

²

2010

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We study the ultralight axion dark matter with mass around 10 −22 eV in f (R) gravity which might resolve the dark energy problem. In particular, we focus on the fact that the pressure of the axion field oscillating in time produces oscillations of gravitational potentials. We show that the oscillation of the gravitational potential is sensitive to the model of gravity. Remarkably, we find that the detectability of the oscillation through the gravitational wave detectors can be significantly enhanced due to the nonlinear resonance between the ultralight axion and the scalaron. PACS numbers: 95.35.+d, 98.62.Gq, 04.50.Kd

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Extended Theories of Gravity

Capozziello

¹

,

Laurentis

²

2011

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Extended Theories of Gravity can be considered a new paradigm to cure shortcomings of General Relativity at infrared and ultraviolet scales. They are an approach that, by preserving the undoubtedly positive results of Einstein's Theory, is aimed to address conceptual and experimental problems recently emerged in Astrophysics, Cosmology and High Energy Physics. In particular, the goal is to encompass, in a self-consistent scheme, problems like Inflation, Dark Energy, Dark Matter, Large Scale Structure and, first of all, to give at least an effective description of Quantum Gravity. We review the basic principles that any gravitational theory has to follow. The geometrical interpretation is discussed in a broad perspective in order to highlight the basic assumptions of General Relativity and its possible extensions in the general framework of gauge theories. Principles of such modifications are presented, focusing on specific classes of theories like f (R)-gravity and scalar-tensor gravity in the metric and Palatini approaches. The special role of torsion is also discussed. The conceptual features of these theories are fully explored and attention is payed to the issues of dynamical and conformal equivalence between them considering also the initial value problem. A number of viability criteria are presented considering the post-Newtonian and the post-Minkowskian limits. In particular, we discuss the problems of neutrino oscillations and gravitational waves in Extended Gravity. Finally, future perspectives of Extended Gravity are considered with possibility to go beyond a trial and error approach.Comment: 184 pages, 3 figures, survey to appear in Physics Report

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Dark energy in the universe, the irreversibility of time and neutrinos

Cited by 3 publications

References 33 publications

Extended Theories of Gravity

Extended Theories of Gravity

NEUTRINO OSCILLATION PHASE DYNAMICALLY INDUCED BY f(R)-GRAVITY

Extended Theories of Gravity

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