scholarly journals Unified emergence of energy scales and cosmic inflation

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Jisuke Kubo ◽  
Jeffrey Kuntz ◽  
Manfred Lindner ◽  
Jonas Rezacek ◽  
Philipp Saake ◽  
...  
Keyword(s):  
Scale Invariance ◽  
Planck Scale ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Spontaneous Breaking ◽  
Type I ◽  
Cosmic Inflation ◽  
Dynamical Generation ◽  
Majorana Neutrinos ◽  
Relic Abundance

Abstract In the quest for unification of the Standard Model with gravity, classical scale invariance can be utilized to dynamically generate the Planck mass MPl. However, the relation of Planck scale physics to the scale of electroweak symmetry breaking μH requires further explanation. In this paper, we propose a model that uses the spontaneous breaking of scale invariance in the scalar sector as a unified origin for dynamical generation of both scales. Using the Gildener-Weinberg approximation, only one scalar acquires a vacuum expectation value of υS ∼ (1016−17) GeV, thus radiatively generating $$ {M}_{\mathrm{P}1}\approx {\beta}_S^{1/2}{\upsilon}_S $$ M P 1 ≈ β S 1 / 2 υ S and μH via the neutrino option with right handed neutrino masses mN = yMυS ∼ 107 GeV. Consequently, active SM neutrinos are given a mass with the inclusion of a type-I seesaw mechanism. Furthermore, we adopt an unbroken Z2 symmetry and a Z2-odd set of right-handed Majorana neutrinos χ that do not take part in the neutrino option and are able to produce the correct dark matter relic abundance (dominantly) via inflaton decay. The model also describes cosmic inflation and the inflationary CMB observables are predicted to interpolate between those of R2 and linear chaotic inflationary model and are thus well within the strongest experimental constraints.

scholarly journals Scale-invariance, dynamically induced Planck scale and inflation in the Palatini formulation

2021 ◽  
Vol 2105 (1) ◽  
pp. 012005
Author(s):  
Ioannis D. Gialamas ◽  
Alexandros Karam ◽  
Thomas D. Pappas ◽  
Antonio Racioppi ◽  
Vassilis C. Spanos
Keyword(s):  
Scale Invariance ◽  
Planck Scale ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Scalar Fields ◽  
Scale Invariant ◽  
Expectation Value ◽  
Hilbert Action

Abstract We present two scale invariant models of inflation in which the addition of quadratic in curvature terms in the usual Einstein-Hilbert action, in the context of Palatini formulation of gravity, manages to reduce the value of the tensor-to-scalar ratio. In both models the Planck scale is dynamically generated via the vacuum expectation value of the scalar fields.

scholarly journals Weak scale from Planck scale: Mass scale generation in a classically conformal two-scalar system

2020 ◽  
Vol 2020 (3) ◽  
Author(s):  
Junichi Haruna ◽  
Hikaru Kawai
Keyword(s):  
Scalar Field ◽  
Standard Model ◽  
Planck Scale ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
The Other ◽  
Expectation Value ◽  
Weak Scale ◽  
The Standard Model ◽  
The One

Abstract In the standard model, the weak scale is the only parameter with mass dimensions. This means that the standard model itself cannot explain the origin of the weak scale. On the other hand, from the results of recent accelerator experiments, except for some small corrections, the standard model has increased the possibility of being an effective theory up to the Planck scale. From these facts, it is naturally inferred that the weak scale is determined by some dynamics from the Planck scale. In order to answer this question, we rely on the multiple point criticality principle as a clue and consider the classically conformal $\mathbb{Z}_2\times \mathbb{Z}_2$ invariant two-scalar model as a minimal model in which the weak scale is generated dynamically from the Planck scale. This model contains only two real scalar fields and does not contain any fermions or gauge fields. In this model, due to a Coleman–Weinberg-like mechanism, the one-scalar field spontaneously breaks the $ \mathbb{Z}_2$ symmetry with a vacuum expectation value connected with the cutoff momentum. We investigate this using the one-loop effective potential, renormalization group and large-$N$ limit. We also investigate whether it is possible to reproduce the mass term and vacuum expectation value of the Higgs field by coupling this model with the standard model in the Higgs portal framework. In this case, the one-scalar field that does not break $\mathbb{Z}_2$ can be a candidate for dark matter and have a mass of about several TeV in appropriate parameters. On the other hand, the other scalar field breaks $\mathbb{Z}_2$ and has a mass of several tens of GeV. These results will be verifiable in near-future experiments.

scholarly journals Dynamical generation of quark/lepton mass hierarchy in an extra dimension

2019 ◽  
Vol 2019 (12) ◽  
Author(s):  
Yukihiro Fujimoto ◽  
Kouhei Hasegawa ◽  
Kenji Nishiwaki ◽  
Makoto Sakamoto ◽  
Kazunori Takenaga ◽  
...  
Keyword(s):  
Extra Dimension ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Casimir Energy ◽  
Mass Hierarchy ◽  
Point Interactions ◽  
Quark Masses ◽  
Dynamical Generation ◽  
Charged Leptons ◽  
Experimental Values

Abstract We show that the observed quark/lepton mass hierarchy can be realized dynamically on an interval extra dimension with point interactions. In our model, the positions of the point interactions play a crucial role in controlling the quark/lepton mass hierarchy and are determined by the minimization of the Casimir energy. By use of the exact extra-dimensional coordinate-dependent vacuum expectation value of a gauge-singlet scalar, we find that there is a parameter set, where the positions of the point interactions are stabilized and fixed, which can reproduce the experimental values of the quark masses precisely enough, while the charged lepton part is less relevant. We also show that possible mixings among the charged leptons will improve the situation significantly.

scholarly journals SPONTANEOUS VIOLATION OF LORENTZ INVARIANCE AND ULTRA-HIGH ENERGY COSMIC RAYS

2003 ◽  
Vol 12 (07) ◽  
pp. 1279-1287 ◽  
Author(s):  
J. W. MOFFAT
Keyword(s):  
Cosmic Rays ◽  
Lorentz Invariance ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
High Energy ◽  
Spontaneous Breaking ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
High Energies ◽  
Local Lorentz Invariance

We propose that local Lorentz invariance is spontaneously violated at high energies, due to a nonvanishing vacuum expectation value of a vector field ϕμ, as a possible explanation of the observation of ultra-high energy cosmic rays with an energy above the GZK cutoff. Certain consequences of spontaneous breaking of Lorentz invariance in cosmology are discussed.

scholarly journals The Super-Stückelberg procedure and dS in pure supergravity

2020 ◽  
Vol 476 (2237) ◽  
pp. 20200035 ◽  
Author(s):  
Silvia Nagy ◽  
Antonio Padilla ◽  
Ivonne Zavala
Keyword(s):  
Cosmological Constant ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Accelerated Expansion ◽  
Spontaneous Breaking ◽  
De Sitter ◽  
Expectation Value ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Natural Way

Understanding de Sitter space in supergravity—and string theory—has led to an intense amount of work for more than two decades, largely motivated by the discovery of the accelerated expansion of the Universe in 1998. In this paper, we consider a non-trivial generalization of unimodular gravity to minimal N = 1 supergravity, which allows for de Sitter solutions without the need of introducing any matter. We formulate a superspace version of the Stückelberg procedure, which restores diffeomorphism and local supersymmetry invariance. This introduces the goldstino associated with spontaneous breaking of supersymmetry in a natural way. The cosmological constant and gravitino mass are related to the vacuum expectation value of the components of a Lagrange multiplier imposing a super-unimodularity condition.

scholarly journals The radion as a dark matter candidate

2018 ◽  
Vol 33 (24) ◽  
pp. 1850144
Author(s):  
Fayez Abu-Ajamieh
Keyword(s):  
Dark Matter ◽  
Scale Invariance ◽  
Spontaneous Breaking ◽  
Newtonian Gravity ◽  
Dark Matter Candidate ◽  
The Future ◽  
Scale Breaking ◽  
Age Of The Universe ◽  
Relic Abundance ◽  
The Universe

I study a class of Randall–Sundrum (RS) models with Spontaneous Breaking of Scale Invariance (SBSI). This class of models implements the Contino–Pomarol–Rattazzi (CPR) mechanism to achieve SBSI through the small running of an external close-to-marginal scale-breaking operator that leads to a light dilaton/radion with couplings to matter suppressed by the small running. I show that for radion masses [Formula: see text] KeV, it can serve as a dark matter (DM) candidate, with a lifetime longer than the age of the universe, and show that the experimental bounds from LHC, non-Newtonian gravity and Axion-Like Particle (ALP) searches allow for the existence of such a radion. In spite of the small relic abundance of the light radion produced in this model, we show that it could be possible to obtain the required abundance through additional assumptions, an issue we postpone to the future.

scholarly journals Nonlinear vacuum electrodynamics and spontaneous breaking of Lorentz symmetry

2020 ◽  
Vol 35 (27) ◽  
pp. 2050174
Author(s):  
C. A. Escobar ◽  
R. Potting
Keyword(s):  
Lorentz Invariance ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Lorentz Symmetry ◽  
Spontaneous Breaking ◽  
Effective Hamiltonian ◽  
First Order ◽  
Superluminal Motion ◽  
Field Fluctuations ◽  
Nonlinear Vacuum Electrodynamics

We study spontaneous breaking of Lorentz symmetry in nonlinear vacuum electrodynamics. Using a first-order formulation of the latter proposed by Plebański, we apply a Dirac constraint analysis and derive an effective Hamiltonian. We show that there exists a large class of potentials for which the effective Hamiltonian is bounded from below, while at the same time possessing local minima in which the field strength acquires a nonzero vacuum expectation value, thereby breaking Lorentz invariance spontaneously. These possible vacua can be classified in four classes, depending on the way Lorentz symmetry is broken. We show that the small field fluctuations around these vacua involve modes for which the dynamics can develop degeneracies, resulting in shock-wave-like and/or superluminal motion. Finally, we study the physical applicability of these models, and show how the Lorentz breaking vacua might in principle be detected by coupling the model to a suitable external current, or to gravity.

scholarly journals Clues on the Majorana scale from scalar resonances at the LHC

2017 ◽  
Vol 32 (06) ◽  
pp. 1750035 ◽  
Author(s):  
Oliver Fischer
Keyword(s):  
Hadron Collider ◽  
Planck Scale ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
High Energy ◽  
Mass Scale ◽  
Particle Spectrum ◽  
Neutrino Sector ◽  
Decay Properties ◽  
The Hill

In order to address the observation of the neutrino oscillations and the metastability of the Standard Model (SM), we extend the fermion sector with two right-handed (i.e. sterile) neutrinos, and the scalar sector of the SM with a real scalar, the Hill field. The latter takes the role of a Majoron and generates the Majorana masses for the neutrino sector, such that the particle spectrum features two CP-even scalars h1 and h2, and also two heavy, mass degenerate neutrinos. When the h1 is identified with the scalar resonance at [Formula: see text] 125 GeV and the condition is imposed that the h1 self-coupling and its running vanish at the Planck scale, the scalar mixing and the vacuum expectation value of the Hill field are fixed by the h2 mass. The h2 can be searched for at the LHC, and it has prospects of being discovered for the target integrated luminosities of the HL-LHC and the Future Circular hadron Collider (FCC-hh) when its mass is on the weak scale. The knowledge of the h2 mass and its decay properties can yield an insight into its coupling to the heavy neutrinos, and thus also on the heavy neutrino mass scale. This yields an interesting connection between potentially detectable heavy scalars in high-energy proton collisions and the mass scale of the heavy neutrinos that is testable at the LHC and at future colliders.

scholarly journals A scalar potential from gauge condensation and its implications

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Eung Jin Chun ◽  
Chengcheng Han
Keyword(s):  
Scalar Potential ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
New Physics ◽  
Kinetic Term ◽  
Electroweak Symmetry ◽  
Abelian Gauge ◽  
Gauge Sector ◽  
Dynamical Generation ◽  
Shed Light

AbstractWe consider a scalar field $$\phi $$ ϕ whose coupling to the kinetic term of a non-abelian gauge field is set at an UV scale M. Then the confinement of the gauge sector will induce a $$\phi $$ ϕ -dependent vacuum energy which generates a dimensionful potential for the scalar. It provides a good example of dynamical generation of a new physics scale below M through the vacuum expectation value $$\langle \phi \rangle $$ ⟨ ϕ ⟩ . This mechanism may shed light on the origin of dark matter, or spontaneous symmetry breaking applicable to the electroweak symmetry.

FERMION SPECTRA AND KM MATRICES IN A LEFT-RIGHT SYMMETRIC MODEL FROM CALABI-YAU STRING COMPACTIFICATION

1993 ◽  
Vol 08 (29) ◽  
pp. 5235-5263
Author(s):  
CHUICHIRO HATTORI ◽  
MASAHISA MATSUDA ◽  
TAKEO MATSUOKA ◽  
DAIZO MOCHINAGA
Keyword(s):  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Current Data ◽  
Fourth Generation ◽  
Spontaneous Breaking ◽  
Neutrino Masses ◽  
Symmetric Model ◽  
Seesaw Mechanism ◽  
Flavor Changing ◽  
O 10

We study a left-right symmetric type of the effective low-energy theory induced from the four-generation superstring model. The spontaneous breaking of the R-parity occurs through a nonzero vacuum expectation value (VEV) of the fourth generation right-handed sneutrino (νR). It is predicted that the lightest chargino is lighter than 113 GeV. By virtue of the seesaw mechanism we can explain the smallness of neutrino masses for three generations and the largeness of the fourth generation neutrino mass. The mixing in the color-singlet sector yields nontrivial KM matrices which bring about flavor-changing interactions. If we take νR=O(10 TeV ), our results are consistent with the current data except for the solar neutrino problem.

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