entropy-logo

Journal Browser

Journal Browser

Particle Theory and Theoretical Cosmology—Dedicated to Professor Paul Howard Frampton on the Occasion of His 80th Birthday

A special issue of Entropy (ISSN 1099-4300). This special issue belongs to the section "Astrophysics, Cosmology, and Black Holes".

Deadline for manuscript submissions: closed (30 April 2024) | Viewed by 9739

Special Issue Editors


E-Mail Website
Guest Editor
Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235, USA
Interests: theoretical elementary particle physics; field theory; cosmology

E-Mail Website
Guest Editor
Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento and INFN-Lecce, Via Arnesano, 73100 Lecce, Italy
Interests: particle theory; theoretical cosmology

Special Issue Information

Dear Colleagues,

This volume is dedicated to Paul Frampton's 80th birthday and his long, productive career in theoretical physics. His Oxford DPhil thesis in 1968 focused on current algebra and superconvergence sum rules, while other early work concerned the dual resonance model. He held postdoc positions at the University of Chicago, CERN, Syracuse, UCLA, and Harvard before settling at the University of North Carolina at Chapel Hill in 1980. Paul has made many contributions to a wide range of research areas, including particle theory, quantum field theory, string theory and cosmology. These include the chiral color model, the 331 model, models of family and flavor symmetry, anomalies in higher dimensions, the black hole entropy, the cyclic cosmology model, and primordial black hole dark matter theory. He has published over 500 papers, collaborated with 166 co-authors, including 3 Nobel winners, giving innumerable conference talks, colloquia and seminars. Paul is a Fellow of the American Association for the Advancement of Science and the American Physical Society. In 1987, he was the project director for the Superconducting Supercollider in North Carolina. From 1996, until his retirement, he was the Louis D. Rubin, Jr. Distinguished Professor of physics and astronomy at the University of North Carolina at Chapel Hill. He is currently affiliated with the Department of Mathematics and Physics of the University of Salento, in Italy. Consequently, topics covered in this volume range widely, covering theoretical physics and including particle theory, particle phenomenology, BSM models, astro-particle physics, dark matter, dark energy, black hole entropy, early-universe thermodynamics, and cosmology. Submissions should also fall within the scope of the journal, i.e., that manuscripts contain entropy/thermodynamic-related content.

Prof. Dr. Thomas W. Kephart
Prof. Dr. Paul Howard Frampton
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Entropy is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • particle theory
  • gauge anomalies
  • particle phenomenology
  • BSM models
  • 331 model
  • string phenomenology
  • astro-particle physics
  • dark matter
  • dark energy
  • black hole entropy
  • early universe thermodynamics and cosmology

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (12 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review, Other

20 pages, 408 KiB  
Article
String Invention, Viable 3-3-1 Model, Dark Matter Black Holes
by Holger B. Nielsen
Entropy 2024, 26(10), 830; https://doi.org/10.3390/e26100830 - 30 Sep 2024
Abstract
With our very limited memories, we provide a brief review of Paul Frampton’s memories of the discovery of the Veneziano model, with this indeed being string theory, with Y. Nambu, and, secondly, his 3-3-1 theory. The latter is, indeed, a non-excluded replacement for [...] Read more.
With our very limited memories, we provide a brief review of Paul Frampton’s memories of the discovery of the Veneziano model, with this indeed being string theory, with Y. Nambu, and, secondly, his 3-3-1 theory. The latter is, indeed, a non-excluded replacement for the Standard Model with triangle anomalies being cancelled, as they must in a truly viable theory. It even needs (essentially) three as the family number! Moreover, primordial black holes as dark matter is mentioned. We end with a review of my own very speculative, utterly recent idea that for the purpose of the classical approximation, we could, using the functional integral as our rudimentary assumption taken over from quantum mechanics, obtain the equations of motion without the, in our opinion, very mysterious imaginary unit i, which usually occurs as a factor in the exponent of the functional integrand, which is this i times the action. The functional integral without the mysterious i leads to the prediction of some of the strongest features in cosmology, and also seems to argue for as few black holes as possible and for the cosmological constant being zero. Full article
Show Figures

Figure 1

11 pages, 276 KiB  
Article
Status of Electromagnetically Accelerating Universe
by Paul H. Frampton
Entropy 2024, 26(8), 629; https://doi.org/10.3390/e26080629 - 26 Jul 2024
Cited by 2 | Viewed by 444
Abstract
To describe the dark side of the universe, we adopt a novel approach where dark energy is explained as an electrically charged majority of dark matter. Dark energy, as such, does not exist. The Friedmann equation at the present time coincides with that [...] Read more.
To describe the dark side of the universe, we adopt a novel approach where dark energy is explained as an electrically charged majority of dark matter. Dark energy, as such, does not exist. The Friedmann equation at the present time coincides with that in a conventional approach, although the cosmological “constant” in the Electromagnetic Accelerating Universe (EAU) Model shares a time dependence with the matter component. Its equation of state is ωP/ρ ≡ −1 within observational accuracy. Full article
9 pages, 243 KiB  
Article
Flipped Quartification: Product Group Unification with Leptoquarks
by James B. Dent, Thomas W. Kephart, Heinrich Päs and Thomas J. Weiler
Entropy 2024, 26(7), 533; https://doi.org/10.3390/e26070533 - 21 Jun 2024
Viewed by 467
Abstract
The quartification model is an SU(3)4 extension with a bi-fundamental fermion sector of the well-known SU(3)3 bi-fundamentalfication model. An alternative “flipped” version of the quartification model is obtained by rearrangement of the particle [...] Read more.
The quartification model is an SU(3)4 extension with a bi-fundamental fermion sector of the well-known SU(3)3 bi-fundamentalfication model. An alternative “flipped” version of the quartification model is obtained by rearrangement of the particle assignments. The flipped model has two standard (bi-fundamentalfication) families and one flipped quartification family. In contrast to traditional product group unification models, flipped quartification stands out by featuring leptoquarks and thus allows for new mechanisms to explain the generation of neutrino masses and possible hints of lepton-flavor non-universality. Full article
15 pages, 290 KiB  
Article
Analytic Formulae for T Violation in Neutrino Oscillations
by Osamu Yasuda
Entropy 2024, 26(6), 472; https://doi.org/10.3390/e26060472 - 29 May 2024
Viewed by 464
Abstract
Recently, a concept known as μTRISTAN, which involves the acceleration of μ+, has been proposed. This initiative has led to considerations of a new design for a neutrino factory. Additionally, leveraging the polarization of μ+, measurements of T [...] Read more.
Recently, a concept known as μTRISTAN, which involves the acceleration of μ+, has been proposed. This initiative has led to considerations of a new design for a neutrino factory. Additionally, leveraging the polarization of μ+, measurements of T violation in neutrino oscillations are also being explored. In this paper, we present analytical expressions for T violation in neutrino oscillations within the framework of standard three-flavor neutrino oscillations, a scenario involving nonstandard interactions, and a case of unitarity violation. We point out that examining the energy spectrum of T violation may be useful for probing new physics effects. Full article
9 pages, 260 KiB  
Article
Dark Matter and Mirror World
by Rabindra N. Mohapatra
Entropy 2024, 26(4), 282; https://doi.org/10.3390/e26040282 - 26 Mar 2024
Viewed by 1042
Abstract
Overwhelming astronomical evidence for dark matter and absence of any laboratory evidence for it despite many dedicated searches have fueled speculation that dark matter may reside in a parallel universe interacting with the familiar universe only via gravitational interactions as well as possibly [...] Read more.
Overwhelming astronomical evidence for dark matter and absence of any laboratory evidence for it despite many dedicated searches have fueled speculation that dark matter may reside in a parallel universe interacting with the familiar universe only via gravitational interactions as well as possibly via some ultra-weak forces. In this scenario, we postulate that the visible universe co-exists with a mirror world consisting of an identical duplicate of forces and matter of our world, obeying a mirror symmetry. This picture, motivated by particle physics considerations, not only provides a natural candidate for dark matter but also has the potential to explain the matter dark matter coincidence problem, i.e., why the dark matter content of the universe is only a few times the visible matter content. One requirement for mirror models is that the mirror world must be colder than our world to maintain the success of big bang nucleosynthesis. After a review of the basic features of the model, we present several new results: first is that the consistency between the coldness of the mirror world and the explanation of the matter dark matter coincidence implies an upper bound on the inflation reheat temperature of the universe to be around 106.5 GeV. We also argue that the coldness implies the mirror world consists mainly of mirror Helium and very little mirror hydrogen, which is the exact opposite of what we see in the visible world. Full article
12 pages, 794 KiB  
Article
Weak Scale Supersymmetry Emergent from the String Landscape
by Howard Baer, Vernon Barger, Dakotah Martinez and Shadman Salam
Entropy 2024, 26(3), 275; https://doi.org/10.3390/e26030275 - 21 Mar 2024
Cited by 2 | Viewed by 939
Abstract
Superstring flux compactifications can stabilize all moduli while leading to an enormous number of vacua solutions, each leading to different 4d laws of physics. While the string landscape provides at present the only plausible explanation for the size of the cosmological [...] Read more.
Superstring flux compactifications can stabilize all moduli while leading to an enormous number of vacua solutions, each leading to different 4d laws of physics. While the string landscape provides at present the only plausible explanation for the size of the cosmological constant, it may also predict the form of weak scale supersymmetry which is expected to emerge. Rather general arguments suggest a power-law draw to large soft terms, but these are subject to an anthropic selection of a not-too-large value for the weak scale. The combined selection allows one to compute relative probabilities for the emergence of supersymmetric models from the landscape. Models with weak scale naturalness appear most likely to emerge since they have the largest parameter space on the landscape. For finetuned models such as high-scale SUSY or split SUSY, the required weak scale finetuning shrinks their parameter space to tiny volumes, making them much less likely to appear compared to natural models. Probability distributions for sparticle and Higgs masses from natural models show a preference for Higgs mass mh125 GeV, with sparticles typically beyond the present LHC limits, in accord with data. From these considerations, we briefly describe how natural SUSY is expected to be revealed at future LHC upgrades. This article is a contribution to the Special Edition of the journal Entropy, honoring Paul Frampton on his 80th birthday. Full article
Show Figures

Figure 1

22 pages, 347 KiB  
Article
Bilocal Field Theory for Composite Scalar Bosons
by Christopher T. Hill
Entropy 2024, 26(2), 146; https://doi.org/10.3390/e26020146 - 8 Feb 2024
Cited by 1 | Viewed by 934
Abstract
We give a bilocal field theory description of a composite scalar with an extended binding potential that reduces to the Nambu–Jona-Lasinio (NJL) model in the pointlike limit. This provides a description of the internal dynamics of the bound state and features a static [...] Read more.
We give a bilocal field theory description of a composite scalar with an extended binding potential that reduces to the Nambu–Jona-Lasinio (NJL) model in the pointlike limit. This provides a description of the internal dynamics of the bound state and features a static internal wave function, ϕ(r), in the center-of-mass frame that satisfies a Schrödinger–Klein–Gordon equation with eigenvalues m2. We analyze the “coloron” model (single perturbative massive gluon exchange) which yields a UV completion of the NJL model. This has a BCS-like enhancement of its interaction, Nc the number of colors, and is classically critical with gcritical remarkably close to the NJL quantum critical coupling. Negative eigenvalues for m2 lead to spontaneous symmetry breaking, and the Yukawa coupling of the bound state to constituent fermions is emergent. Full article
Show Figures

Figure 1

Review

Jump to: Research, Other

10 pages, 333 KiB  
Review
Hunting for Bileptons at Hadron Colliders
by Gennaro Corcella
Entropy 2024, 26(10), 850; https://doi.org/10.3390/e26100850 - 8 Oct 2024
Abstract
I review possible signals at hadron colliders of bileptons, namely doubly charged vectors or scalars with lepton number L=±2, as predicted by a 331 model, based on a [...] Read more.
I review possible signals at hadron colliders of bileptons, namely doubly charged vectors or scalars with lepton number L=±2, as predicted by a 331 model, based on a SU(3)c×SU(3)L×U(1)X symmetry. In particular, I account for a version of the 331 model wherein the embedding of the hypercharge is obtained with the addition of three exotic quarks and vector bileptons. Furthermore, a sextet of SU(3)L, necessary to provide masses to leptons, yields an extra scalar sector, including a doubly charged Higgs, i.e., scalar bileptons. As bileptons are mostly produced in pairs at hadron colliders, their main signal is provided by two same-sign lepton pairs at high invariant mass. Nevertheless, they can also decay according to non-leptonic modes, such as a TeV-scale heavy quark, charged 4/3 or 5/3, plus a Standard Model quark. I explore both leptonic and non-leptonic decays and the sensitivity to the processes of the present and future hadron colliders. Full article
Show Figures

Figure 1

28 pages, 509 KiB  
Review
The SU(3)C × SU(3)L × U(1)X (331) Model: Addressing the Fermion Families Problem within Horizontal Anomalies Cancellation
by Claudio Corianò and Dario Melle
Entropy 2024, 26(5), 420; https://doi.org/10.3390/e26050420 - 14 May 2024
Viewed by 877
Abstract
One of the most important and unanswered problems in particle physics is the origin of the three generations of quarks and leptons. The Standard Model does not provide any hint regarding its sequential charge assignments, which remain a fundamental mystery of Nature. One [...] Read more.
One of the most important and unanswered problems in particle physics is the origin of the three generations of quarks and leptons. The Standard Model does not provide any hint regarding its sequential charge assignments, which remain a fundamental mystery of Nature. One possible solution of the puzzle is to look for charge assignments, in a given gauge theory, that are inter-generational, by employing the cancellation of the gravitational and gauge anomalies horizontally. The 331 model, based on an SU(3)C×SU(3)L×U(1)X does this in an economical way and defines a possible extension of the Standard Model, where the number of families has necessarily to be three. We review the model in Pisano, Pleitez, and Frampton’s formulation, which predicts the existence of bileptons. Another characteristics of the model is to unify the SU(3)C×SU(2)L×U(1)X into the 331 symmetry at a scale that is in the TeV range. Expressions of the scalar mass eigenstates and of the renormalization group equations of the model are also presented. Full article
Show Figures

Figure 1

16 pages, 1187 KiB  
Review
Flavor’s Delight
by Hans Peter Nilles and Saúl Ramos-Sánchez
Entropy 2024, 26(5), 355; https://doi.org/10.3390/e26050355 - 24 Apr 2024
Cited by 3 | Viewed by 803
Abstract
Discrete flavor symmetries provide a promising approach to understand the flavor sector of the standard model of particle physics. Top-down (TD) explanations from string theory reveal two different types of such flavor symmetries: traditional and modular flavor symmetries that combine to the eclectic [...] Read more.
Discrete flavor symmetries provide a promising approach to understand the flavor sector of the standard model of particle physics. Top-down (TD) explanations from string theory reveal two different types of such flavor symmetries: traditional and modular flavor symmetries that combine to the eclectic flavor group. There have been many bottom-up (BU) constructions to fit experimental data within this scheme. We compare TD and BU constructions to identify the most promising groups and try to give a unified description. Although there is some progress in joining BU and TD approaches, we point out some gaps that have to be closed with future model building. Full article
Show Figures

Figure 1

Other

Jump to: Research, Review

6 pages, 163 KiB  
Perspective
Quo Vadis Particula Physica?
by Xavier Calmet
Entropy 2024, 26(5), 366; https://doi.org/10.3390/e26050366 - 26 Apr 2024
Viewed by 801
Abstract
In this brief paper, I give a very personal account on the state of particle physics on the occasion of Paul Frampton’s 80th birthday. Full article
9 pages, 273 KiB  
Perspective
Particle Physics and Cosmology Intertwined
by Pran Nath
Entropy 2024, 26(2), 110; https://doi.org/10.3390/e26020110 - 25 Jan 2024
Viewed by 886
Abstract
While the standard model accurately describes data at the electroweak scale without the inclusion of gravity, beyond the standard model, physics is increasingly intertwined with gravitational phenomena and cosmology. Thus, the gravity-mediated breaking of supersymmetry in supergravity models leads to sparticle masses, which [...] Read more.
While the standard model accurately describes data at the electroweak scale without the inclusion of gravity, beyond the standard model, physics is increasingly intertwined with gravitational phenomena and cosmology. Thus, the gravity-mediated breaking of supersymmetry in supergravity models leads to sparticle masses, which are gravitational in origin, observable at TeV scales and testable at the LHC, and supergravity also provides a candidate for dark matter, a possible framework for inflationary models and for models of dark energy. Further, extended supergravity models and string and D-brane models contain hidden sectors, some of which may be feebly coupled to the visible sector, resulting in heat exchange between the visible and hidden sectors. Because of the couplings between the sectors, both particle physics and cosmology are affected. The above implies that particle physics and cosmology are intrinsically intertwined in the resolution of essentially all of the cosmological phenomena, such as dark matter and dark energy, and in the resolution of cosmological puzzles, such as the Hubble tension and the EDGES anomaly. Here, we give a brief overview of the intertwining and its implications for the discovery of sparticles, as well as the resolution of cosmological anomalies and the identification of dark matter and dark energy as major challenges for the coming decades. Full article
Back to TopTop