Escape from supercooling with or without bubbles: gravitational wave signatures

Quasi-conformal models are an appealing scenario that can offer naturally a strongly supercooled phase transition and a period of thermal inflation in the early Universe. A crucial aspect for the viability of these models is how the Universe escapes from the supercooled state. One possibility is that thermal inflation phase ends by nucleation and percolation of true vacuum bubbles. This route is not, however, always efficient. In such case another escape mechanism, based on the growth of quantum fluctuations of the scalar field that eventually destabilize the false vacuum, becomes relevant. We study both of these cases in detail in a simple yet representative model. We determine the duration of the thermal inflation, the curvature power spectrum generated for the scales that exit horizon during the thermal inflation, and the stochastic gravitational wave background from the phase transition. We show that these gravitational waves provide an observable signal from the thermal inflation in almost the entire parameter space of interest. Furthermore, the shape of the gravitational wave spectrum can be used to ascertain how the Universe escaped from supercooling.

Dark energy from nondegenerate Higgs-vacuum

Scalar fields are favorite among the possible candidates for the dark energy. Most frequently discussed are those with degenerate minima at [Formula: see text]. In this paper, a slightly modified two-Higgs doublet model is taken to contain the Higgs field(s) as the dark energy candidate(s). The model considered has two nondegenerate minima at [Formula: see text], instead of one degenerate minimum at [Formula: see text]. The component fields of one SU(2) doublet ([Formula: see text]) act as the standard model (SM) Higgs, while the component fields of the second doublet ([Formula: see text]) are taken to be the dark energy candidates (lying in the true vacuum). It is found that one can arrange for late time acceleration (dark energy) by using an SU(2) Higgs doublet, whose vacuum expectation value is zero, in the quintessential regime.

Explaining Defects of the Universal Vacua with Black Holes-Hedgehogs and Strings

Assuming the Multiple Point Principle (MPP) as a new law of Nature, we considered the existence of the two degenerate vacua of the Universe: (a) the first Electroweak (EW) vacuum at v 1 ≈ 246 GeV—“true vacuum”, and (b) the second Planck scale “false vacuum” at v 2 ∼ 10 18 GeV. In these vacua, we investigated different topological defects. The main aim of the paper is an investigation of the black-hole-hedgehogs configurations as defects of the false vacuum. In the framework of the f ( R ) gravity, described by the Gravi-Weak unification model, we considered a black-hole solution, which corresponds to a “hedgehog”—global monopole, that has been “swallowed” by the black-hole with mass core M B H ∼ 10 18 GeV and radius δ ∼ 10 − 21 GeV − 1 . Considering the results of the hedgehog lattice theory in the framework of the S U ( 2 ) Yang-Mills gauge-invariant theory with hedgehogs in the Wilson loops, we have used the critical value of temperature for the hedgehogs’ confinement phase ( T c ∼ 10 18 GeV). This result gave us the possibility to conclude that the SM shows a new physics (with contributions of the S U ( 2 ) -triplet Higgs bosons) at the scale ∼10 TeV. This theory predicts the stability of the EW-vacuum and the accuracy of the MPP.

Explaining Defects of the Universal Vacua with Black Holes-Hedgehogs and Strings

Assuming the Multiple Point Principle (MPP) as a new law of Nature, we considered the existence of the two degenerate vacua of the Universe: a) the first Electroweak (EW) vacuum at $v_1\approx 246$ GeV—“true vacuum”, and b) the second Planck scale “false vacuum” at $v_2 \sim 10^{18}$ GeV. In these vacua, we investigated different topological defects. The main aim of the paper is an investigation of the black-hole-hedgehogs configurations as defects of the false vacuum. In the framework of the $f(R)$ gravity, described by the Gravi-Weak unification model, we considered a black-hole solution, which corresponds to a “hedgehog”—global monopole, that has been “swallowed” by the black-hole with mass core $M_{BH}\sim 10^{18}$ GeV and radius $\delta\sim 10^{-21}$ GeV$^{-1}$. Considering the results of the hedgehog lattice theory in the framework of the $SU(2)$ Yang-Mills gauge-invariant theory with hedgehogs in the Wilson loops, we have used the critical value of temperature for the hedgehogs’ confinement phase ($T_c\sim 10^{18}$ GeV). This result gave us the possibility to conclude that the SM shows a new physics (with contributions of the $SU(2)$-triplet Higgs bosons) at the scale $\sim 10$ TeV. This theory predicts the stability of the EW-vacuum and the accuracy of the MPP.

Gravi-weak unification and the black-hole-hedgehog’s solution with magnetic field contribution

In the present paper, we investigated the gravitational black-hole-hedgehog’s solution with magnetic field contribution in the framework of the [Formula: see text]-gravity described by the Gravi-weak unification (GWU) model. Assuming the Multiple Point Principle (MPP), we considered the existence of the two degenerate vacua of the Universe: the first Electroweak (EW)-vacuum with [Formula: see text] GeV (“true vacuum”), and the second Planck scale (“false vacuum”) with [Formula: see text] GeV. In these vacua, we investigated different topological defects. The main aim of this paper is an investigation of the black-hole-hedgehog configurations as defects of the “false vacuum.” We have obtained the solution which corresponds to a global monopole, that has been “swallowed” by the black-hole with core mass [Formula: see text] GeV and radius [Formula: see text] GeV[Formula: see text]. We investigated the metric in the vicinity of the black-hole-hedgehog and estimated its horizon radius: [Formula: see text]. We have considered the phase transition from the “false vacuum” to the “true vacuum” and confirmed the stability of the EW-vacuum.

Phase transitions and topological defects

As the early universe cools down, it may perform transitions to phases with more and more broken symmetries. In a first-order phase transition, fields may be trapped in the false vacuum; the rate of the resulting tunneling process to the true vacuum is derived. Phase transitions can lead also to the formation of topological defects. Their structure and the reason for their stability are discussed.

Gravitational black-holes-hedgehogs and two degenerate vacua of the Universe

In the present paper, assuming the Multiple Point Principle (MPP) as a new law of Nature, we considered the existence of the two degenerate vacua of the Universe: the first Electroweak (EW) vacuum at [Formula: see text][Formula: see text]GeV — “true vacuum”, and the second Planck scale “false vacuum” at [Formula: see text] GeV. In these vacua, we investigated different topological defects. The main aim of this paper is an investigation of the black-hole-hedgehogs configurations as defects of the false vacuum. In the framework of the [Formula: see text] gravity, described by the Gravi-Weak unification model, we considered a black-hole solution, which corresponds to a “hedgehog” — global monopole, that has been “swallowed” by the black-hole with mass core [Formula: see text][Formula: see text]GeV and radius [Formula: see text][Formula: see text]GeV[Formula: see text]. Considering the results of the hedgehog lattice theory in the framework of the [Formula: see text] Yang–Mills gauge-invariant theory with hedgehogs in the Wilson loops, we have used the critical value of temperature for the hedgehogs confinement phase ([Formula: see text][Formula: see text]GeV). This result gave us the possibility to conclude that the SM shows a new physics with contributions of the [Formula: see text]-triplet Higgs bosons at the scale [Formula: see text][Formula: see text]TeV. Theory predicts the stability of the EW-vacuum and the accuracy of the MPP.

Power law expansion of the early universe for a V (a) = kan potential

In a recent paper, He, Gao and Cai [Phys. Rev. D 89, 083510 (2014)], found a rigorous proof, based on analytical solutions of the Wheeler–DeWitt (WDWE) equation, of the spontaneous creation of the universe from nothing. The solutions were obtained from a classical potential [Formula: see text], where [Formula: see text] is the scale factor. In this paper, we present a complementary (to that of He, Gao and Cai) solution to the WDWE equation with [Formula: see text]. I have found an exponential expansion of the true vacuum bubble for all scenarios. In all scenarios, we found a power law behavior of the scale factor result which is in agreement with another studies.