scholarly journals Inflation near a metastable de Sitter vacuum from moduli stabilisation

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Ignatios Antoniadis ◽  
Osmin Lacombe ◽  
George K. Leontaris
Keyword(s):  
Realistic Model ◽  
Intermediate Energy ◽  
De Sitter ◽  
World Sheet ◽  
A Value ◽  
String Loop ◽  
Hybrid Inflation ◽  
Perturbative Quantum ◽  
De Sitter Vacuum ◽  
Energy Physics

AbstractWe study the cosmological properties of a metastable de Sitter vacuum obtained recently in the framework of type IIB flux compactifications in the presence of three D7-brane stacks, based on perturbative quantum corrections at both world-sheet and string loop level that are dominant at large volume and weak coupling. In the simplest case, the model has one effective parameter controlling the shape of the potential of the inflaton which is identified with the volume modulus. The model provides a phenomenological successful small-field inflation for a value of the parameter that makes the minimum very shallow and near the maximum. The horizon exit is close to the inflection point while most of the required e-folds of the Universe expansion are generated near the minimum, with a prediction for the ratio of tensor-to-scalar primordial fluctuations $$r\simeq 4\times 10^{-4}$$ r ≃ 4 × 10 - 4 . Despite its shallowness, the minimum turns out to be practically stable. We show that it can decay only through the Hawking–Moss instanton leading to an extremely long decay rate. Obviously, in order to end inflation and obtain a realistic model, new low-energy physics is needed around the minimum, at intermediate energy scales of order $$10^{12}$$ 10 12 GeV. An attractive possibility is by introducing a “waterfall” field within the framework of hybrid inflation.

scholarly journals Hybrid inflation and waterfall field in string theory from D7-branes

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Ignatios Antoniadis ◽  
Osmin Lacombe ◽  
George K. Leontaris
Keyword(s):  
String Theory ◽  
Flux Compactifications ◽  
Saddle Point ◽  
Present State ◽  
Global Minimum ◽  
Vacuum Energy ◽  
De Sitter ◽  
Hybrid Inflation ◽  
De Sitter Vacuum ◽  
The Universe

Abstract We present an explicit string realisation of a cosmological inflationary scenario we proposed recently within the framework of type IIB flux compactifications in the presence of three magnetised D7-brane stacks. Inflation takes place around a metastable de Sitter vacuum. The inflaton is identified with the volume modulus and has a potential with a very shallow minimum near the maximum. Inflation ends due to the presence of “waterfall” fields that drive the evolution of the Universe from a nearby saddle point towards a global minimum with tuneable vacuum energy describing the present state of our Universe.

scholarly journals Squeezed states in the de Sitter vacuum

2003 ◽  
Vol 68 (6) ◽  
Author(s):  
Martin B. Einhorn ◽  
Finn Larsen
Keyword(s):  
Squeezed States ◽  
De Sitter ◽  
De Sitter Vacuum

scholarly journals Dynamics of Electromagnetic Fields and Structure of Regular Rotating Electrically Charged Black Holes and Solitons in Nonlinear Electrodynamics Minimally Coupled to Gravity

Universe ◽  
2019 ◽  
Vol 5 (10) ◽  
pp. 205 ◽  
Author(s):  
Irina Dymnikova ◽  
Evgeny Galaktionov
Keyword(s):  
Black Holes ◽  
Electromagnetic Fields ◽  
Nonlinear Electrodynamics ◽  
Axially Symmetric ◽  
De Sitter ◽  
Dynamical Equations ◽  
Naked Singularities ◽  
Charged Black Holes ◽  
De Sitter Vacuum ◽  
Electrically Charged

We study the dynamics of electromagnetic fields of regular rotating electrically charged black holes and solitons replacing naked singularities in nonlinear electrodynamics minimally coupled to gravity (NED-GR). They are related by electromagnetic and gravitational interactions and described by the axially symmetric NED-GR solutions asymptotically Kerr-Newman for a distant observer. Geometry is described by the metrics of the Kerr-Schild class specified by T t t = T r r ( p r = − ρ ) in the co-rotating frame. All regular axially symmetric solutions obtained from spherical solutions with the Newman-Janis algorithm belong to this class. The basic generic feature of all regular objects of this class, both electrically charged and electrically neutral, is the existence of two kinds of de Sitter vacuum interiors. We analyze the regular solutions to dynamical equations for electromagnetic fields and show which kind of a regular interior is favored by electromagnetic dynamics for NED-GR objects.

scholarly journals Graviatoms with de Sitter Interior

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Irina Dymnikova ◽  
Michael Fil’chenkov
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Dark Energy ◽  
Charged Particle ◽  
Energy Spectrum ◽  
Primordial Black Hole ◽  
De Sitter ◽  
Fundamental Symmetry ◽  
Gravitational Vacuum ◽  
De Sitter Vacuum

We present a graviatom with de Sitter interior as a new candidate to atomic dark matter generically related to a vacuum dark energy through its de Sitter vacuum interior. It is a gravitationally bound quantum system consisting of a nucleus represented by a regular primordial black hole (RPBH), its remnant or gravitational vacuum soliton G-lump, and a charged particle. We estimate probability of formation of RPBHs and G-lumps in the early Universe and evaluate energy spectrum and electromagnetic radiation of graviatom which can in principle bear information about a fundamental symmetry scale responsible for de Sitter interior and serve as its observational signatures.

ON THE SUPERSTRING HAMILTONIAN IN THE FRIEDMANN SPACE–TIME

2006 ◽  
Vol 15 (06) ◽  
pp. 845-868 ◽  
Author(s):  
M. D. POLLOCK
Keyword(s):  
Cosmological Solution ◽  
Vacuum State ◽  
Einstein Condensate ◽  
De Sitter ◽  
Superstring Theory ◽  
Bose Einstein Condensate ◽  
Higher Derivative ◽  
Effective Lagrangian ◽  
State Formula ◽  
De Sitter Vacuum

The ten-dimensional effective Lagrangian [Formula: see text] for the gravitational sector of the heterotic superstring theory is known up to quartic higher-derivative order [Formula: see text]. In cosmology, the reduced, four-dimensional line element assumes the Friedmann form ds2 = dt2 - a(t)2dx2, where t is comoving time and a(t) ≡ a0eα(t) is the radius function of the three-space dx2, whose curvature is k = 0, ± 1. The four-Lagrangian can then be expressed as the power-series [Formula: see text], where ˙ ≡ d/dt, from which the field equation can be derived by the method of Ostrogradsky. Here, we determine the coefficients Λ0, An, Bn, Cn, and Kn, which are all non-vanishing in general. We recover the previously obtained, high-curvature, anti-de Sitter vacuum state [Formula: see text] with effective cosmological constant Λ = {18/[175ζ(3) - 1/2]}1/3A r κ-2, whose existence makes it possible to envisage a singularity-free and horizon-free cosmological solution, stable to linear perturbations. It is interesting that all the coefficients of quartic origin arise from the near-cancellation of sums of opposite sign but magnitude f ≈ (28.6–369) times larger than the answer. They thus exhibit a slight asymmetry with regard to positive and negative energies, the anti-de Sitter vacuum being characterized by positive Nordström energy, and therefore only accessible at high curvatures. This vacuum state is a Bose–Einstein condensate of non-interacting gravitons at zero temperature, which, referred to comoving time, can only be formulated after the Wick rotation t → ±iτ, resulting in an imaginary horizon.

scholarly journals Dark Matter Candidates with Dark Energy Interiors Determined by Energy Conditions

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 662 ◽  
Author(s):  
Irina Dymnikova
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Energy Condition ◽  
Phantom Energy ◽  
Weak Energy Condition ◽  
Energy Conditions ◽  
De Sitter ◽  
Dynamical Equations ◽  
De Sitter Vacuum ◽  
Observational Signature

We outline the basic properties of regular black holes, their remnants and self-gravitating solitons G-lumps with the de Sitter and phantom interiors, which can be considered as heavy dark matter (DM) candidates generically related to a dark energy (DE). They are specified by the condition T t t = T r r and described by regular solutions of the Kerr-Shild class. Solutions for spinning objects can be obtained from spherical solutions by the Newman-Janis algorithm. Basic feature of all spinning objects is the existence of the equatorial de Sitter vacuum disk in their deep interiors. Energy conditions distinguish two types of their interiors, preserving or violating the weak energy condition dependently on violation or satisfaction of the energy dominance condition for original spherical solutions. For the 2-nd type the weak energy condition is violated and the interior contains the phantom energy confined by an additional de Sitter vacuum surface. For spinning solitons G-lumps a phantom energy is not screened by horizons and influences their observational signatures, providing a source of information about the scale and properties of a phantom energy. Regular BH remnants and G-lumps can form graviatoms binding electrically charged particles. Their observational signature is the electromagnetic radiation with the frequencies depending on the energy scale of the interior de Sitter vacuum within the range available for observations. A nontrivial observational signature of all DM candidates with de Sitter interiors predicted by analysis of dynamical equations is the induced proton decay in an underground detector like IceCUBE, due to non-conservation of baryon and lepton numbers in their GUT scale false vacuum interiors.

scholarly journals Mass, Spacetime Symmetry, de Sitter Vacuum, and the Higgs Mechanism

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 634 ◽  
Author(s):  
Irina Dymnikova
Keyword(s):  
Higgs Mechanism ◽  
Minimal Length ◽  
Length Scale ◽  
False Vacuum ◽  
De Sitter ◽  
Negative Mass ◽  
Spacetime Symmetry ◽  
Generic Relation ◽  
Minimal Length Scale ◽  
De Sitter Vacuum

We address the question of the intrinsic relation between mass, gravity, spacetime symmetry, and the Higgs mechanism implied by involvement of the de Sitter vacuum as its basic ingredient (a false vacuum). Incorporating the de Sitter vacuum, the Higgs mechanism implicitly incorporates the generic relation between mass, gravity, and spacetime symmetry revealed in the frame of General Relativity for all objects involving the de Sitter vacuum. We overview two observational cases which display and verify this relation, the case known as “negative mass square problem” for neutrino, and appearance of a minimal length scale in e + e − annihilation.

scholarly journals Deriving the inflaton in compactified M-theory with a de Sitter vacuum

2019 ◽  
Vol 100 (6) ◽  
Author(s):  
Gordon Kane ◽  
Martin Wolfgang Winkler
Keyword(s):  
De Sitter ◽  
De Sitter Vacuum ◽  
M Theory
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