scholarly journals TESTING AXION PHYSICS IN A JOSEPHSON JUNCTION ENVIRONMENT

2011 ◽  
Vol 26 (38) ◽  
pp. 2841-2852 ◽  
Author(s):  
CHRISTIAN BECK
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Josephson Junction ◽  
Quantum Entanglement ◽  
Early Universe ◽  
Josephson Junctions ◽  
Parameter Values

We suggest that experiments based on Josephson junctions, SQUIDS, and coupled Josephson qubits may be used to construct a resonant environment for dark matter axions. We propose experimental setups in which axionic interaction strengths in a Josephson junction environment can be tested, similar in nature to recent experiments that test for quantum entanglement of two coupled Josephson qubits. We point out that the parameter values relevant for early-universe axion cosmology are accessible with present day's achievements in nanotechnology. We work out how typical dark matter and dark energy signals would look like in a novel detector that exploits this effect.

scholarly journals ACCELERATION AND DECELERATION IN THE CURVATURE-INDUCED PHANTOM MODEL OF THE LATE AND FUTURE UNIVERSE: COSMIC COLLAPSE AND ITS QUANTUM ESCAPE

2009 ◽  
Vol 18 (05) ◽  
pp. 865-887
Author(s):  
S. K. SRIVASTAVA ◽  
J. DUTTA
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Quantum Gravity ◽  
Cosmological Constant ◽  
Early Universe ◽  
High Energy ◽  
High Energy Density ◽  
Energy Models ◽  
Acceleration And Deceleration ◽  
The Universe

In this paper, the cosmology of the late and future universe is obtained from f(R) gravity with nonlinear curvature terms R2 and R3 (R is the Ricci scalar curvature). It is different from f(R) dark energy models where nonlinear curvature terms are taken as a gravitational alternative to dark energy. In the present model, neither linear nor nonlinear curvature terms are taken as dark energy. Rather, dark energy terms are induced by curvature terms and appear in the Friedmann equation derived from f(R) gravitational equations. This approach has an advantage over f(R) dark energy models in three ways: (i) results are consistent with WMAP observations, (ii) dark matter is produced from the gravitational sector and (iii) the universe expands as ~ t2/3 during dominance of the curvature-induced dark matter, which is consistent with the standard cosmology. Curvature-induced dark energy mimics phantom and causes late acceleration. It is found that transition from matter-driven deceleration to acceleration takes place at the redshift 0.36 at time 0.59 t0 (t0 is the present age of the universe). Different phases of this model, including acceleration and deceleration during the phantom phase, are investigated. It is found that expansion of the universe will stop at the age of 3.87 t0 + 694.4 kyr. After this epoch, the universe will contract and collapse by the time of 336.87 t0 + 694.4 kyr. Further, it is shown that cosmic collapse obtained from classical mechanics can be avoided by making quantum gravity corrections relevant near the collapse time due to extremely high energy density and large curvature analogous to the state of the very early universe. Interestingly, the cosmological constant is also induced here; it is extremely small in the classical domain but becomes very high in the quantum domain. This result explains the largeness of the cosmological constant in the early universe due to quantum gravity effects during this era and its very low value in the present universe due to negligible quantum effect in the late universe.

scholarly journals LITTLE RIP AND PSEUDO RIP PHENOMENA FROM COUPLED DARK ENERGY

2013 ◽  
Vol 28 (37) ◽  
pp. 1350172 ◽  
Author(s):  
I. BREVIK ◽  
A. V. TIMOSHKIN ◽  
Y. RABOCHAYA
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Equation Of State ◽  
Early Universe ◽  
Equations Of State ◽  
Cosmological Models ◽  
Ideal Fluids ◽  
Interaction Term ◽  
Gravitational Equations

We consider Little Rip (LR) and Pseudo Rip (PR) cosmological models with two interacting ideal fluids, corresponding to dark energy and dark matter. The interaction between the dark energy and the dark matter fluid components is described in terms of the parameters in the equations of state for the LR and PR universes. In contrast to a model containing only a pure dark energy, the presence of the interaction term between the fluid components in the gravitational equations leads to a modification of the equation of state parameters. The properties of the early universe in this formalism are pointed out.

scholarly journals Dark Matter and Dark Energy in the Universe

2018 ◽  
Vol 14 (1) ◽  
pp. 5292-5295
Author(s):  
Yuanjie Li ◽  
Lihong Zhang ◽  
Peng Dong
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Dark Energy ◽  
Early Universe ◽  
Left Behind ◽  
Time Quantum ◽  
The Universe

This paper points out that not only all quantum-ghost puzzles occur in the Time Quantum Worm Hole, but also the dark matter in the universe is hidden in it. Dark energy is the contribution of the Planck black hole left behind by the early universe.

scholarly journals There is no coincidence after all!

2020 ◽  
Vol 29 (14) ◽  
pp. 2043013
Author(s):  
Saurya Das
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Early Universe ◽  
Negative Pressure ◽  
Einstein Condensate ◽  
Coincidence Problem ◽  
Bose Einstein Condensate ◽  
Bose Einstein ◽  
Equal Density

We show that if Dark Matter is made up of light bosons, they form a Bose–Einstein condensate in the early Universe. This in turn naturally induces a Dark Energy of approximately equal density and exerting negative pressure. This explains the so-called coincidence problem.

Inflation, dark matter, and dark energy

2019 ◽  
pp. 423-464
Author(s):  
Malcolm S. Longair ◽  
Chris Smeenk
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Power Spectrum ◽  
Early Universe ◽  
Particle Physics ◽  
Large Scale ◽  
Initial State ◽  
Large Scale Structures ◽  
Initial Power ◽  
The Universe

The success of the ΛCDM model has raised a number of challenging problems for the origin of structure in the universe and the initial state from which it evolved. The origins of these basic cosmological problems are described. The dark matter must be non-baryonic, but its nature has not been established. Likewise, the nature of the dark energy is not understood. The inflationary model for the very early universe has had some undoubted successes in accounting for the initial power-spectrum of fluctuations from which large-scale structures formed but there is no physical realization of the inflaton field. Defects formed during phase transitions in the early universe cannot account for the initial power spectrum of fluctuations, but may have some part to play in structure formation. The origin of the baryon-antibaryon asymmetry in the early universe is not understood in terms of theories of particle physics.

Effective masses in a dense fermion background — Applied to neutrinos, dark matter and dark energy

2014 ◽  
Vol 29 (21) ◽  
pp. 1444010
Author(s):  
Bruce H. J. McKellar ◽  
T. J. Goldman ◽  
G. J. Stephenson
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Scalar Field ◽  
Effective Mass ◽  
Negative Pressure ◽  
Expectation Value ◽  
Effective Masses ◽  
Neutrino Astrophysics

If fermions interact with a scalar field, and there are many fermions present the scalar field may develop an expectation value and generate an effective mass for the fermions. This can lead to the formation of fermion clusters, which could be relevant for neutrino astrophysics and for dark matter astrophysics. Because this system may exhibit negative pressure, it also leads to a model of dark energy.

scholarly journals Dark matter freeze-in from semi-production

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Andrzej Hryczuk ◽  
Maxim Laletin
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Cross Section ◽  
Thermal Equilibrium ◽  
Indirect Detection ◽  
Production Mechanism ◽  
Number Density ◽  
Matter Production ◽  
Relic Density ◽  
Standard Formalism

Abstract We study a novel dark matter production mechanism based on the freeze-in through semi-production, i.e. the inverse semi-annihilation processes. A peculiar feature of this scenario is that the production rate is suppressed by a small initial abundance of dark matter and consequently creating the observed abundance requires much larger coupling values than for the usual freeze-in. We provide a concrete example model exhibiting such production mechanism and study it in detail, extending the standard formalism to include the evolution of dark matter temperature alongside its number density and discuss the importance of this improved treatment. Finally, we confront the relic density constraint with the limits and prospects for the dark matter indirect detection searches. We show that, even if it was never in full thermal equilibrium in the early Universe, dark matter could, nevertheless, have strong enough present-day annihilation cross section to lead to observable signals.

scholarly journals Sterile neutrino dark matter from generalized CPT -symmetric early-Universe cosmologies

2021 ◽  
Vol 104 (2) ◽  
Author(s):  
Adam Duran ◽  
Logan Morrison ◽  
Stefano Profumo
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Sterile Neutrino

scholarly journals Displaced new physics at colliders and the early universe before its first second

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Lorenzo Calibbi ◽  
Francesco D’Eramo ◽  
Sam Junius ◽  
Laura Lopez-Honorez ◽  
Alberto Mariotti
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Upper Bound ◽  
New Physics ◽  
Early History ◽  
Relic Density ◽  
History Of ◽  
Indirect Information ◽  
The Universe

Abstract Displaced vertices at colliders, arising from the production and decay of long-lived particles, probe dark matter candidates produced via freeze-in. If one assumes a standard cosmological history, these decays happen inside the detector only if the dark matter is very light because of the relic density constraint. Here, we argue how displaced events could very well point to freeze-in within a non-standard early universe history. Focusing on the cosmology of inflationary reheating, we explore the interplay between the reheating temperature and collider signatures for minimal freeze-in scenarios. Observing displaced events at the LHC would allow to set an upper bound on the reheating temperature and, in general, to gather indirect information on the early history of the universe.

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