scholarly journals WHY SUPERSYMMETRY SHOULD BE RESTORED AT THE TeV SCALE

2008 ◽  
Vol 17 (13n14) ◽  
pp. 2521-2525
Author(s):  
M. GASPERINI
Keyword(s):  
Energy Density ◽  
Large Scale ◽  
Vacuum Energy ◽  
Space Time ◽  
Susy Breaking ◽  
Vacuum Energy Density ◽  
Spatial Dimensions ◽  
Bulk Space ◽  
Breaking Scale

It is explained why the curvature associated with the vacuum energy density arising from SUSY breaking cannot be completely transferred to the extra spatial dimensions of a bulk space–time manifold, and it is shown — without using hierarchy arguments but only the results of current large-scale observations — why the TeV scale should correspond to the maximal allowed SUSY-breaking scale.

scholarly journals DARK ENERGY DENSITY IN MODELS WITH SPLIT SUPERSYMMETRY AND DEGENERATE VACUA

2012 ◽  
Vol 27 (11) ◽  
pp. 1250063 ◽  
Author(s):  
C. FROGGATT ◽  
R. NEVZOROV ◽  
H. B. NIELSEN
Keyword(s):  
Dark Energy ◽  
Energy Density ◽  
Cosmological Constant ◽  
Vacuum Energy ◽  
Susy Breaking ◽  
Vacuum Energy Density ◽  
Dark Energy Density ◽  
Hidden Sector ◽  
Split Supersymmetry ◽  
Breaking Scale

In N = 1 supergravity supersymmetric and nonsupersymmetric Minkowski vacua originating in the hidden sector can be degenerate. In the supersymmetric phase in flat Minkowski space, nonperturbative supersymmetry breakdown may take place in the observable sector, inducing a nonzero and positive vacuum energy density. Assuming that such a supersymmetric phase and the phase in which we live are degenerate, we estimate the value of the cosmological constant. We argue that the observed value of the dark energy density can be reproduced in the split SUSY scenario of SUSY breaking if the SUSY breaking scale is of order of 1010 GeV.

scholarly journals Predicting the SUSY breaking scale in SUGRA models with degenerate vacua

2020 ◽  
Vol 35 (01) ◽  
pp. 2050007
Author(s):  
C. D. Froggatt ◽  
R. Nevzorov ◽  
H. B. Nielsen ◽  
A. W. Thomas
Keyword(s):  
Renormalization Group ◽  
Energy Density ◽  
Vacuum Energy ◽  
Scalar Potential ◽  
Susy Breaking ◽  
Vacuum Energy Density ◽  
Second Phase ◽  
Dark Energy Density ◽  
High Energies ◽  
Breaking Scale

In [Formula: see text] supergravity, the scalar potential may have supersymmetric (SUSY) and nonsupersymmetric Minkowski vacua (associated with supersymmetric and physical phases) with vanishing energy density. In the supersymmetric Minkowski (second) phase, some breakdown of SUSY may be induced by nonperturbative effects in the observable sector that give rise to a tiny positive vacuum energy density. Postulating the exact degeneracy of the physical and second vacua as well as assuming that at high energies the couplings in both phases are almost identical, one can estimate the dark energy density in these vacua. It is mostly determined by the SUSY breaking scale [Formula: see text] in the physical phase. Exploring the two-loop renormalization group (RG) flow of couplings in these vacua, we find that the measured value of the cosmological constant can be reproduced if [Formula: see text] varies from 20 TeV to 400 TeV. We also argue that this prediction for the SUSY breaking scale is consistent with the upper bound on [Formula: see text] in the higgsino dark matter scenario.

scholarly journals Space-Time Curvature Of General Relativity And Energy Density Of A Three-Dimensional Quantum Vacuu

2015 ◽  
Vol 69 (1) ◽  
Author(s):  
Davide Fiscaletti ◽  
Amrit Sorli
Keyword(s):  
General Relativity ◽  
Energy Density ◽  
Vacuum Energy ◽  
Three Dimensional ◽  
Space Time ◽  
Vacuum Energy Density ◽  
Quantum Vacuum ◽  
Vacuum Condensate ◽  
Interesting Solution ◽  
Variable Energy

AbstractA three-dimensional quantum vacuum condensate is introduced as a fundamental medium from which gravity emerges in a geometro-hydrodynamic limit. In this approach, the curvature of space-time characteristic of general relativity is obtained as a mathematical value of a more fundamental actual variable energy density of quantum vacuum which has a concrete physical meaning. The fluctuations of the quantum vacuum energy density suggest an interesting solution for the dark energy problem.

scholarly journals Some String Cosmological Models in Bianchi Type III Space-Time with Magnetic Field and Vacuum Energy Density

2018 ◽  
Author(s):  
Raj Bali ◽  
Subhash Bola
Keyword(s):  
Magnetic Field ◽  
Energy Density ◽  
Vacuum Energy ◽  
Bianchi Type ◽  
Space Time ◽  
Cosmological Models ◽  
Energy Conditions ◽  
Vacuum Energy Density ◽  
Type Iii ◽  
Special Cases

Bianchi type III string cosmological models (massive and geometric) in presence of magnetic field with vacuum energy density following the techniques used by Letelier (1979) and Stachel (1980) are obtained. We find that the energy conditions (dominant as well as weak) given by Hawking and Ellis (1974) are satisfied for the models. Also the solutions obtained satisfy conservation equation for massive string with magnetic field and vacuum energy density. The models in general, represent anisotropic phase of space-time due to the presence of string. However, the models isotropize at late time and in special case. It has also been shown that the magnetic field is directly linked with the matter. For string dust model, the state finder parameters {r,s} are in excellent agreement with Planck results (Sahni et al. (2003)). The physical and geometrical aspects of the models with special cases are also discussed.

Quantum fields and gravity: Expanding space-times

2020 ◽  
Vol 35 (02n03) ◽  
pp. 2040039
Author(s):  
Claudio Parmeggiani
Keyword(s):  
Energy Density ◽  
Vacuum Energy ◽  
Fock Space ◽  
Zero Point ◽  
Big Bang ◽  
Space Time ◽  
Vacuum Energy Density ◽  
Dimensional Manifold ◽  
Quantum Fields ◽  
Point Energy

We discuss a proposal for a somewhat new formulation of quantum field theory (set in a four-dimensional manifold, the space-time) that includes an analysis of its implications for the evolution of Einstein-Friedmann cosmological models. The proposed theory displays two peculiar features: (i) a local Hilbert-Fock space is associated with each space-time point: we are dealing with a vector bundle whose fibers are Hilbert spaces; the operator-valued sections of the bundle are the quantum fields; (ii) the vacuum energy density is finite, being regularized in a space-time curvature dependent way, independently at each point. In fact everything is finite: self-masses, self-charges, quantum fluctuations: they depend on the space-time curvature and diverge only for a flat metric. In an Einstein-Friedmann model the vacuum (zero-point) energy density is consequently time-dependent and in general not negligible. Then it is shown that, for some choices of the parameters of the theory, the big-bang singularity is resolved and replaced by a bounce driven by the vacuum energy density, which becomes (very) large and negative near the bounce (negative by the contribution of the Fermi fields). But for large times (now, say) the Bose fields’ positive vacuum energy eventually overcomes the negative one and we are finally left with the present vacuum energy: positive and reasonably small.

scholarly journals LOCAL CONTRIBUTION OF A QUANTUM CONDENSATE TO THE VACUUM ENERGY DENSITY

2003 ◽  
Vol 18 (10) ◽  
pp. 683-690 ◽  
Author(s):  
GIOVANNI MODANESE
Keyword(s):  
Energy Density ◽  
Vacuum Energy ◽  
Casimir Effect ◽  
Landau Equation ◽  
Vacuum Energy Density ◽  
Negative Effects ◽  
Ginzburg Landau ◽  
Physical Conditions ◽  
Local Contribution ◽  
Gravitational Vacuum

We evaluate the local contribution gμνL of coherent matter with Lagrangian density L to the vacuum energy density. Focusing on the case of superconductors obeying the Ginzburg–Landau equation, we express the relativistic invariant density L in terms of low-energy quantities containing the pairs density. We discuss under which physical conditions the sign of the local contribution of the collective wave function to the vacuum energy density is positive or negative. Effects of this kind can play an important role in bringing the local changes in the amplitude of gravitational vacuum fluctuations — a phenomenon reminiscent of the Casimir effect in QED.

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