Effective action study of the 𝒫𝒯-symmetric (iϕ3)6−𝜖 theory and the Yang–Lee edge singularity

We use the effective potential method to study the [Formula: see text]-symmetric [Formula: see text] field theory in [Formula: see text] space–time dimensions. For [Formula: see text], we obtained the first two energy levels which are real as well as reflecting the stability of the spectrum. [Formula: see text]-symmetry breaking occurs at [Formula: see text] where the two levels merge and beyond this critical point they have complex values. Since there exist no results in the literature to compare with, we extracted the critical exponents of the theory to test the accuracy of our calculations where we find them agree with exact results from the literature. We showed that the critical point is in fact a Yang–Lee edge singularity which is the first time to link [Formula: see text]-symmetry breaking to the existence of a Yang–Lee edge singularity. For [Formula: see text], the fixed point is nontrivial and exists for negative [Formula: see text] values as expected from Yang–Lee theory for ferromagnetic systems.

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New Transition and Energy Levels of Three-Times Ionized Krypton (Kr IV)

Atoms ◽

10.3390/atoms9030048 ◽

2021 ◽

Vol 9 (3) ◽

pp. 48

Author(s):

M. Raineri ◽

M. Gallardo ◽

J. Reyna Almandos ◽

A. G. Trigueiros ◽

C. J. B. Pagan

Keyword(s):

Transition Probabilities ◽

Energy Levels ◽

Pulsed Discharge ◽

Core Polarization ◽

Polarization Effects ◽

Hartree Fock ◽

Theta Pinch ◽

New Energy ◽

First Time

A capillary pulsed-discharge and a theta-pinch were used to record Kr spectra in the region of 330–4800 Å. A set of 168 transitions of these spectra were classified for the first time. We extended the analysis to twenty-five new energy levels belonging to 3s23p24d, 3s23p25d even configurations. We calculated weighted transition probabilities (gA) for all of the experimentally observed lines and lifetimes for new energy levels using a relativistic Hartree–Fock method, including core-polarization effects.

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Asymmetry underlies stability in power grids

Nature Communications ◽

10.1038/s41467-021-21290-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Ferenc Molnar ◽

Takashi Nishikawa ◽

Adilson E. Motter

Keyword(s):

Symmetry Breaking ◽

Real World ◽

Power Grids ◽

Stable Operation ◽

World Systems ◽

Symmetric State ◽

Network Systems ◽

Additional Improvement ◽

The Stability ◽

General Method

AbstractBehavioral homogeneity is often critical for the functioning of network systems of interacting entities. In power grids, whose stable operation requires generator frequencies to be synchronized—and thus homogeneous—across the network, previous work suggests that the stability of synchronous states can be improved by making the generators homogeneous. Here, we show that a substantial additional improvement is possible by instead making the generators suitably heterogeneous. We develop a general method for attributing this counterintuitive effect to converse symmetry breaking, a recently established phenomenon in which the system must be asymmetric to maintain a stable symmetric state. These findings constitute the first demonstration of converse symmetry breaking in real-world systems, and our method promises to enable identification of this phenomenon in other networks whose functions rely on behavioral homogeneity.

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The Dirac Sea, T and C Symmetry Breaking, and the Spinor Vacuum of the Universe

Universe ◽

10.3390/universe7050124 ◽

2021 ◽

Vol 7 (5) ◽

pp. 124

Author(s):

Vadim Monakhov

Keyword(s):

Field Theory ◽

Quantum Field Theory ◽

Symmetry Breaking ◽

Momentum Space ◽

Quantum Field ◽

Conjugation Operator ◽

Dirac Sea ◽

Canonical Anticommutation Relations ◽

The Universe ◽

Dirac Conjugation

We have developed a quantum field theory of spinors based on the algebra of canonical anticommutation relations (CAR algebra) of Grassmann densities in the momentum space. We have proven the existence of two spinor vacua. Operators C and T transform the normal vacuum into an alternative one, which leads to the breaking of the C and T symmetries. The CPT is the real structure operator; it preserves the normal vacuum. We have proven that, in the theory of the Dirac Sea, the formula for the charge conjugation operator must contain an additional generalized Dirac conjugation operator.

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Conformal Regge theory at finite boost

Journal of High Energy Physics ◽

10.1007/jhep05(2021)059 ◽

2021 ◽

Vol 2021 (5) ◽

Author(s):

Simon Caron-Huot ◽

Joshua Sandor

Keyword(s):

Field Theory ◽

Operator Product Expansion ◽

Operator Product ◽

Exact Results ◽

Double Integral ◽

Regge Theory ◽

Conformal Field ◽

Regge Trajectories ◽

Continuous Spins ◽

Regge Limit

Abstract The Operator Product Expansion is a useful tool to represent correlation functions. In this note we extend Conformal Regge theory to provide an exact OPE representation of Lorenzian four-point correlators in conformal field theory, valid even away from Regge limit. The representation extends convergence of the OPE by rewriting it as a double integral over continuous spins and dimensions, and features a novel “Regge block”. We test the formula in the conformal fishnet theory, where exact results involving nontrivial Regge trajectories are available.

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Tachyons and Solitons in Spontaneous Symmetry Breaking in the Frame of Field Theory

Symmetry ◽

10.3390/sym13081358 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1358

Author(s):

Yiannis Contoyiannis ◽

Michael P. Hanias ◽

Pericles Papadopoulos ◽

Stavros G. Stavrinides ◽

Myron Kampitakis ◽

...

Keyword(s):

Symmetry Breaking ◽

Spontaneous Symmetry Breaking ◽

Critical Point ◽

Universality Class ◽

Lattice Simulation ◽

Ginzburg Landau ◽

Spin Lattice ◽

Nuclear Collisions ◽

Ising Spin ◽

Relativistic Nuclear Collisions

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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A Novel Approach to Fabricate Foam Ceramics from Steel Slag

Advances in Materials Science and Engineering ◽

10.1155/2020/4649082 ◽

2020 ◽

Vol 2020 ◽

pp. 1-7

Author(s):

Yu Zheng ◽

Xudong Luo ◽

Jinlong Yang ◽

Wenlong Huo ◽

Chi Kang

Keyword(s):

Compressive Strength ◽

Ph Value ◽

Steel Slag ◽

Raw Material ◽

Solid Loading ◽

Insulation Material ◽

Ceramic Foams ◽

Novel Approach ◽

The Stability ◽

First Time

A novel approach is used for fabricating steel slag foam ceramics based on the particle-stabilized foaming method. In this work, steel slag was used as the raw material and propyl gallate (PG) was used as the surface modifier. For the first time, steel slag ceramic foams were successfully fabricated based on particle-stabilized foams. The results show that the stability of the ceramic foams was closely related to the pH value and PG concentration. The porosity and compressive strength could be controlled by changing the solid loading of steel slag and sintering temperature. The porosity of steel slag foam ceramics ranged from 85.6% to 62.53%, and the compressive strength was from 1.74 MPa to 10.42 MPa. The thermal conductivity of steel slag foam ceramics was only 0.067 W (m·K)−1, which shows that it could be used as a thermal insulation material.

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Temporal Stability and Biodiversity of Two Complex Antilisterial Cheese-Ripening Microbial Consortia

Applied and Environmental Microbiology ◽

10.1128/aem.69.7.4012-4018.2003 ◽

2003 ◽

Vol 69 (7) ◽

pp. 4012-4018 ◽

Cited By ~ 86

Author(s):

Ariel Maoz ◽

Ralf Mayr ◽

Siegfried Scherer

Keyword(s):

Species Composition ◽

Bacterial Species ◽

Temporal Stability ◽

Individual Characteristics ◽

Microbial Consortia ◽

Cheese Ripening ◽

Safe Food ◽

The Stability ◽

The Individual ◽

First Time

ABSTRACT The temporal stability and diversity of bacterial species composition as well as the antilisterial potential of two different, complex, and undefined microbial consortia from red-smear soft cheeses were investigated. Samples were collected twice, at 6-month intervals, from each of two food producers, and a total of 400 bacterial isolates were identified by Fourier-transform infrared spectroscopy and 16S ribosomal DNA sequence analysis. Coryneform bacteria represented the majority of the isolates, with certain species being predominant. In addition, Marinolactobacillus psychrotolerans, Halomonas venusta, Halomonas variabilis, Halomonas sp. (106 to 107 CFU per g of smear), and an unknown, gram-positive bacterium (107 to 108 CFU per g of smear) are described for the first time in such a consortium. The species composition of one consortium was quite stable over 6 months, but the other consortium revealed less diversity of coryneform species as well as less stability. While the first consortium had a stable, extraordinarily high antilisterial potential in situ, the antilisterial activity of the second consortium was lower and decreased with time. The cause for the antilisterial activity of the two consortia remained unknown but is not due to the secretion of soluble, inhibitory substances by the individual components of the consortium. Our data indicate that the stability over time and a potential antilisterial activity are individual characteristics of the ripening consortia which can be monitored and used for safe food production without artificial preservatives.

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NEUTRINO COUPLING TO COSMOLOGICAL BACKGROUND: A REVIEW ON GRAVITATIONAL BARYO/LEPTOGENESIS

International Journal of Modern Physics D ◽

10.1142/s0218271813300309 ◽

2013 ◽

Vol 22 (12) ◽

pp. 1330030 ◽

Cited By ~ 31

Author(s):

GAETANO LAMBIASE ◽

SUBHENDRA MOHANTY ◽

ARAGAM R. PRASANNA

Keyword(s):

Field Theory ◽

Gravitational Field ◽

Thermal Equilibrium ◽

Energy Levels ◽

Lepton Number ◽

Cpt Symmetry ◽

Cosmological Background ◽

The Universe ◽

General Conditions ◽

Lepton Number Violating

In this paper, we review the theories of origin of matter–antimatter asymmetry in the universe. The general conditions for achieving baryogenesis and leptogenesis in a CPT conserving field theory have been laid down by Sakharov. In this review, we discuss scenarios where a background scalar or gravitational field spontaneously breaks the CPT symmetry and splits the energy levels between particles and antiparticles. Baryon or Lepton number violating processes in proceeding at thermal equilibrium in such backgrounds gives rise to Baryon or Lepton number asymmetry.

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Extended analysis of Xe VII and Xe VIII

Canadian Journal of Physics ◽

10.1139/cjp-2016-0728 ◽

2017 ◽

Vol 95 (9) ◽

pp. 805-810 ◽

Cited By ~ 1

Author(s):

M. Raineri ◽

M. Gallardo ◽

J. Reyna Almandos ◽

C.J.B. Pagan ◽

R. Sarmiento

Keyword(s):

Light Source ◽

Energy Levels ◽

Excited Configuration ◽

Pulsed Discharge ◽

Hartree Fock ◽

The Core ◽

New Energy ◽

Extended Analysis ◽

First Time ◽

Atomic Parameters

A pulsed discharge light source to study the six and seven times ionized xenon spectra in the 419–4642 Å region was used. A set of 40 transitions of Xe VII and 25 transitions of Xe VIII were classified for the first time. We revised the values for the previously known energy levels and extended the analysis for Xe VII to 10 new energy levels belonging to 5s6d, 5s7s and 5s7p, 4d95s25p even and odd configurations, respectively. Seven new energy levels of the core excited configuration 4d95s5d of Xe VIII are presented. For the prediction of the atomic parameters, energy levels, and transition, relativistic Hartree–Fock calculations were used.

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A field theory approach to stability of radial equilibria in nonlinear elasticity

Mathematical Proceedings of the Cambridge Philosophical Society ◽

10.1017/s0305004100064513 ◽

1986 ◽

Vol 99 (3) ◽

pp. 589-604 ◽

Cited By ~ 22

Author(s):

J. Sivaloganathan

Keyword(s):

Field Theory ◽

Calculus Of Variations ◽

Nonlinear Elasticity ◽

Isotropic Material ◽

Theory Approach ◽

Radial Solutions ◽

Equilibrium Equations ◽

The Stability ◽

State Of Tension

In this paper we study the stability of a class of singular radial solutions to the equilibrium equations of nonlinear elasticity, in which a hole forms at the centre of a ball of isotropic material held in a state of tension under prescribed boundary displacements. The existence of such cavitating solutions has been shown by Ball[1], Stuart [11] and Sivaloganathan[10]. Our methods involve elements of the field theory of the calculus of variations and provide a new unified interpretation of the phenomenon of cavitation.

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