scholarly journals Spontaneous symmetry breaking in the late Universe and glimpses of the early Universe phase transitions à la baryogenesis

Author(s):  
M. Sami ◽  
Radouane Gannouji

Spontaneous symmetry breaking is the foundation of electroweak unification and serves as an integral part of the model building beyond the standard model of particle physics and it also finds interesting applications in the late Universe. We review development related to obtaining the late cosmic acceleration from spontaneous symmetry breaking in the Universe at large scales. This phenomenon is best understood through Ginzburg–Landau theory of phase transitions which we briefly describe. Hereafter, we present elements of spontaneous symmetry breaking in relativistic field theory. We then discuss the “symmetron” scenario-based upon symmetry breaking in the late Universe which is realized by using a specific form of conformal coupling. However, the model is faced with “NO GO” for late-time acceleration due to local gravity constraints. We argue that the problem can be circumvented by using the massless [Formula: see text] theory coupled to massive neutrino matter. As for the early Universe, spontaneous symmetry breaking finds its interesting applications in the study of electroweak phase transition. To this effect, we first discuss in detail the Ginzburg–Landau theory of first-order phase transitions and then apply it to electroweak phase transition including technical discussions on bubble nucleation and sphaleron transitions. We provide a pedagogical exposition of dynamics of electroweak phase transition and emphasize the need to go beyond the standard model of particle physics for addressing the baryogenesis problem. Review ends with a brief discussion on Affleck–Dine mechanism and spontaneous baryogenesis. Appendixes include technical details on essential ingredients of baryogenesis, sphaleron solution, one-loop finite temperature effective potential and dynamics of bubble nucleation.

2021 ◽  
Author(s):  
Vanja Marić ◽  
Gianpaolo Torre ◽  
Fabio Franchini ◽  
Salvatore Giampaolo

Abstract Ginzburg-Landau theory of continuous phase transitions implicitly assumes that microscopic changes are negligible in determining the thermodynamic properties of the system. In this work we provide an example that clearly contrasts with this assumption. In particular, we consider the 2-cluster-Ising model, a one-dimensional spin-1/2 system that is known to exhibit a quantum phase transition between a magnetic and a nematic phase. By imposing boundary conditions that induce topological frustration we show that local order is completely destroyed on both sides of the transition and that the two thermodynamic phases can only be characterized by string order parameters. Having proved that topological frustration is capable of altering the nature of a system's phase transition, this result is a clear challenge to current theories of phase transitions in complex quantum systems.


2012 ◽  
Vol 01 (02) ◽  
pp. 50-51
Author(s):  
Peter Higgs

The story begins in 1960, when Nambu, inspired by the BCS theory of superconductivity, formulated chirally invariant relativistic models of interacting massless fermions in which spontaneous symmetry breaking generates fermionic masses (the analogue of the BCS gap). Around the same time Jeffrey Goldstone discussed spontaneous symmetry breaking in models containing elementary scalar fields (as in Ginzburg-Landau theory). I became interested in the problem of how to avoid a feature of both kinds of model, which seemed to preclude their relevance to the real world, namely the existence in the spectrum of massless spin-zero bosons (Goldstone bosons). By 1962 this feature of relativistic field theories had become the subject of the Goldstone theorem.


2020 ◽  
Vol 30 (1) ◽  
pp. 61
Author(s):  
Binh Dinh Thanh ◽  
Phong Vo Quoc ◽  
Hoang Ngoc Long

The bubble nucleation in the framework of 3-3-1-1 model is studied. Previous studies show that first order electroweak phase transition occurs in two periods. In this paper we evaluate the bubble nucleation temperature throughout the parameter space. Using the stringent condition for bubble nucleation formation we find that in the first period, symmetry breaking from \(SU(3)\rightarrow SU(2)\), the bubble is formed at the nucleation temperature $T=150$ GeV and the lower bound of the scalar mass is 600 GeV. In the second period, symmetry breaking from \((SU(2)\rightarrow U(1)\), only subcritical bubbles are formed. This constraint eliminates the electroweak baryon genesis in the second period of the model.


Author(s):  
Jean Zinn-Justin

In this chapter, a model is considered that can be defined in continuous dimensions, the Gross– Neveu–Yukawa (GNY) model, which involves N Dirac fermions and one scalar field. The model has a continuous U(N) symmetry, and a discrete symmetry, which prevents the addition of a fermion mass term to the action. For a specific value of a coefficient of the action, the model undergoes a continuous phase transition. The broken phase illustrates a mechanism of spontaneous symmetry breaking, leading to spontaneous fermion mass generation like in the Standard Model (SM) of particle physics. In four dimensions, the GNY can be considered as a toy model to represent the interactions between the top quark and the Higgs boson, the heaviest particles of the SM of fundamental interactions, when the gauge fields are omitted. The model is renormalizable in four dimensions and its renormalization group (RG) properties can be studied in d = 4 and d = 4 − ϵ dimensions. A model of self-interacting fermions with the same symmetries and fermion content, the Gross–Neveu (GN) model, has been widely studied. In perturbation theory, for d > 2, it describes only a phase with massless fermions but, in d = 2 + ϵ dimensions, the RG indicates that, at a critical value of the coupling constant, the model experiences a phase transition. In two dimensions, it is renormalizable and exhibits the phenomenon of asymptotic freedom. The massless phase becomes infrared unstable and there is strong evidence that the spectrum corresponds to spontaneous symmetry breaking and fermion mass generation.


Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 733 ◽  
Author(s):  
Eibun Senaha

Symmetries at finite temperature are of great importance to understand dynamics of spontaneous symmetry breaking phenomena, especially phase transitions in early Universe. Some symmetries such as the electroweak symmetry can be restored in hot environment. However, it is a nontrivial question that the phase transition occurs via first or second order, or even smooth crossover, which strongly depends on underlying physics. If it is first order, gravitational waves can be generated, providing a detectable signal of this epoch. Moreover, the baryon asymmetry of the Universe can also arise under some conditions. In this article, the electroweak phase transition is reviewed, focusing particularly on the case of the first-order phase transition. Much attention is paid to multi-step phase transitions in which additional symmetry breaking such as a spontaneous Z 2 breaking plays a pivotal role in broadening the possibility of the first-order electroweak phase transition. On the technical side, we review thermal resummation that mitigates a bad infrared behavior related to the symmetry restoration. In addition, gauge and scheme dependences of perturbative calculations are also briefly discussed.


1999 ◽  
Vol 13 (22n23) ◽  
pp. 791-799
Author(s):  
C. H. EAB ◽  
B. WIWATANAPATAPHEE ◽  
I. M. TANG

A Ginzburg–Landau theory for the multiple structural phase transition observed in the cuprate perovskite structure ceramics is developed. The order parameters Λi for each phase are defined in terms of the deformations which occur in each phase. In terms of the deformation, the expansion of the free energies is to the twelfth order. The theory can account for a second-order tetragonal to orthorhombic-I transition at high temperatures and a first-order orthorhombic-I to orthorhombic-II transition at lower temperatures. The criterion for the existence of a tricritical line is established.


Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1358
Author(s):  
Yiannis Contoyiannis ◽  
Michael P. Hanias ◽  
Pericles Papadopoulos ◽  
Stavros G. Stavrinides ◽  
Myron Kampitakis ◽  
...  

This paper presents our study of the presence of the unstable critical point in spontaneous symmetry breaking (SSB) in the framework of Ginzburg–Landau (G-L) free energy. Through a 3D Ising spin lattice simulation, we found a zone of hysteresis where the unstable critical point continued to exist, despite the system having entered the broken symmetry phase. Within the hysteresis zone, the presence of the kink–antikink SSB solitons expands and, therefore, these can be observed. In scalar field theories, such as Higgs fields, the mass of this soliton inside the hysteresis zone could behave as a tachyon mass, namely as an imaginary quantity. Due to the fact that groups Ζ(2) and SU(2) belong to the same universality class, one expects that, in future experiments of ultra-relativistic nuclear collisions, in addition to the expected bosons condensations, structures of tachyon fields could appear.


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