Bimetric Models. When Negative Mass Replaces Both Dark Matter and Dark Energy. Excellent Agreement with Observational Data. Solv
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Emergence and Phenomenology in Quantum Gravity
Emergence and Phenomenology in Quantum Gravity by Isabeau Premont-Schwarz´ A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Doctor of Philosophy in Physics Waterloo, Ontario, Canada, 2010 © Isabeau Premont-Schwarz´ 2010 AUTHOR’S DECLARATION I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii AUTHORSHIP STATEMENT This thesis is based on the following five articles: • A. Hamma, F. Markopoulou, I. Pr´emont-Schwarz and S. Severini, “Lieb-Robinson bounds and the speed of light from topological order,” Phys. Rev. Lett. 102 (2009) 017204 [arXiv:0808.2495 [quant-ph]]. • I. Pr´emont-Schwarz ,A. Hamma, I. Klich and F. Markopoulou, “Lieb-Robinson bounds for commutator-bounded operators ,” Phys. Rev. A 81, 040102(R) (2010) .[arXiv:0912.4544 [quant-ph]]. • I. Pr´emont-Schwarz and J. Hnybida, “Lieb-Robinson bounds with dependence on interaction strengths, ” [arXiv:1002.4190 [math-ph]]. • L. Modesto and I. Pr´emont-Schwarz, “Self-dual Black Holes in LQG: Theory and Phenomenology,” Phys. Rev. D 80, 064041 (2009) [arXiv:0905.3170 [hep-th]]. • S. Hossenfelder, L. Modesto and I. Pr´emont-Schwarz, “A model for non-singular black hole collapse and evaporation ,” Phys. Rev. D 81, 044036 (2010) [arXiv:0912.1823 [gr-qc]]. I did the majority of the work in the first article, but the project was initiated by Fotini Markopoulou-Kalamara and Alioscia Hamma and the manuscript was mostly written by Alioscia Hamma. -
Negative Energies and Time Reversal in Quantum Field Theory F
Negative Energies and Time Reversal in Quantum Field Theory F. Henry-Couannier To cite this version: F. Henry-Couannier. Negative Energies and Time Reversal in Quantum Field Theory. Global Journal of Science Research, Global Journals™ Incorporated, 2012, 12, pp.39-58. in2p3-00865527 HAL Id: in2p3-00865527 http://hal.in2p3.fr/in2p3-00865527 Submitted on 18 Jan 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License NEGATIVE ENERGIES AND TIME REVERSAL IN QUANTUM FIELD THEORY Frederic Henry-Couannier CPPM, 163 Avenue De Luminy, Marseille 13009 France. [email protected] Abstract The theoretical and phenomenological status of negative energies is reviewed in Quantum Field Theory leading to the conclusion that hope- fully their rehabilitation might only be completed in a modified general relativistic model. 1 Introduction With recent cosmological observations related to supernovae, CMB and galactic clustering the evidence is growing that our universe is undergoing an accelerated expansion at present. Though the most popular way to account for this unex- pected result has been the reintroduction of a cosmological constant or a new kind of dark matter with negative pressure, scalar fields with negative kinetic energy, so-called phantom fields, have recently been proposed [1] [2] [3] as new sources leading to the not excluded possibility that the equation of state param- eter be less than minus one. -
Dark Energy and Dark Matter As Inertial Effects Introduction
Dark Energy and Dark Matter as Inertial Effects Serkan Zorba Department of Physics and Astronomy, Whittier College 13406 Philadelphia Street, Whittier, CA 90608 [email protected] ABSTRACT A disk-shaped universe (encompassing the observable universe) rotating globally with an angular speed equal to the Hubble constant is postulated. It is shown that dark energy and dark matter are cosmic inertial effects resulting from such a cosmic rotation, corresponding to centrifugal (dark energy), and a combination of centrifugal and the Coriolis forces (dark matter), respectively. The physics and the cosmological and galactic parameters obtained from the model closely match those attributed to dark energy and dark matter in the standard Λ-CDM model. 20 Oct 2012 Oct 20 ph] - PACS: 95.36.+x, 95.35.+d, 98.80.-k, 04.20.Cv [physics.gen Introduction The two most outstanding unsolved problems of modern cosmology today are the problems of dark energy and dark matter. Together these two problems imply that about a whopping 96% of the energy content of the universe is simply unaccounted for within the reigning paradigm of modern cosmology. arXiv:1210.3021 The dark energy problem has been around only for about two decades, while the dark matter problem has gone unsolved for about 90 years. Various ideas have been put forward, including some fantastic ones such as the presence of ghostly fields and particles. Some ideas even suggest the breakdown of the standard Newton-Einstein gravity for the relevant scales. Although some progress has been made, particularly in the area of dark matter with the nonstandard gravity theories, the problems still stand unresolved. -
The Negative Energy in Generalized Vaidya Spacetime
universe Communication The Negative Energy in Generalized Vaidya Spacetime Vitalii Vertogradov 1,2 1 Department of the Theoretical Physics and Astronomy, Herzen State Pedagogical University, 191186 St. Petersburg, Russia; [email protected] 2 The SAO RAS, Pulkovskoe Shosse 65, 196140 St. Petersburg, Russia Received: 17 August 2020; Accepted: 17 September 2020; Published: 22 September 2020 Abstract: In this paper we consider the negative energy problem in generalized Vaidya spacetime. We consider several models where we have the naked singularity as a result of the gravitational collapse. In these models we investigate the geodesics for particles with negative energy when the II type of the matter field satisfies the equation of the state P = ar (a 2 [0 , 1]). Keywords: generalized Vaidya spacetime; naked singularity; black hole; negative energy 1. Introduction In 1969 R. Penrose theoretically predicted the effect of the negative energy formation in the Kerr metric during the process of the decay or the collision. Furthermore, the nature of the geodesics for particles with negative energy was investigated [1,2]. It was shown that in the ergosphere of a rotating black hole closed orbits for such particles are absent. This geodesics must appear from the region inside the gravitational radius. Moreover, there was research devoted to the particles with negative energy in Schwarzschild spacetime which was conducted by A. A. Grib and Yu. V. Pavlov [3]. They showed that the particles with negative energy can exist only in the region inside of the event horizon. However, the Schwarzschild black hole is the eternal one and we must consider the gravitational collapse to speak about the past of the geodesics for particles with negative energy. -
A Unifying Theory of Dark Energy and Dark Matter: Negative Masses and Matter Creation Within a Modified ΛCDM Framework J
Astronomy & Astrophysics manuscript no. theory_dark_universe_arxiv c ESO 2018 November 5, 2018 A unifying theory of dark energy and dark matter: Negative masses and matter creation within a modified ΛCDM framework J. S. Farnes1; 2 1 Oxford e-Research Centre (OeRC), Department of Engineering Science, University of Oxford, Oxford, OX1 3QG, UK. e-mail: [email protected]? 2 Department of Astrophysics/IMAPP, Radboud University, PO Box 9010, NL-6500 GL Nijmegen, the Netherlands. Received February 23, 2018 ABSTRACT Dark energy and dark matter constitute 95% of the observable Universe. Yet the physical nature of these two phenomena remains a mystery. Einstein suggested a long-forgotten solution: gravitationally repulsive negative masses, which drive cosmic expansion and cannot coalesce into light-emitting structures. However, contemporary cosmological results are derived upon the reasonable assumption that the Universe only contains positive masses. By reconsidering this assumption, I have constructed a toy model which suggests that both dark phenomena can be unified into a single negative mass fluid. The model is a modified ΛCDM cosmology, and indicates that continuously-created negative masses can resemble the cosmological constant and can flatten the rotation curves of galaxies. The model leads to a cyclic universe with a time-variable Hubble parameter, potentially providing compatibility with the current tension that is emerging in cosmological measurements. In the first three-dimensional N-body simulations of negative mass matter in the scientific literature, this exotic material naturally forms haloes around galaxies that extend to several galactic radii. These haloes are not cuspy. The proposed cosmological model is therefore able to predict the observed distribution of dark matter in galaxies from first principles. -
A Wideband Polarization Survey of the Extragalactic Sky at 2-4 Ghz: A
A Wideband Polarization Survey of the Extragalactic Sky at 2-4 GHz: A Science White Paper for the VLA Sky Survey Sui Ann Mao (NRAO, U Wisconsin Madison, [email protected]), Julie Banfield (CASS, CSIRO), Bryan Gaensler (CAASTRO, University of Sydney), Lawrence Rudnick (U Minnesota), Jeroen Stil (U Calgary), Cormac Purcell (University of Sydney), Rainer Beck (MPIfR), Jamie Farnes (University of Sydney), Shane O’Sullivan (University of Sydney), Dominic Schnitzeler (MPIfR), Tony Willis (DRAO), Xiaohui Sun (Uni- versity of Sydney), Ettore Carretti (CASS, CSRIO), Klaus Dolag (U Munich), Dmitry Sokoloff (Moscow State University), Roland Kothes (DRAO), Maik Wolleben (U Calgary), George Heald (ASTRON), Joern Geisbuesch (DRAO), Tim Robishaw (DRAO), Jose Afonso (Observatorio Astronomico de Lisboa), Antonio Mario Magalh˜aes (U S˜ao Paulo), Britt Lundgren (U Wisconsin Madison), Marijke Haverkorn (Radboud University Nijmegen), Niels Oppermann (CITA), Russ Taylor (U Calgary) Abstract A VLA Sky Survey of the extragalactic sky at S band (2-4 GHz) with polarization information can uniquely probe the magneto-ionic medium in a wide range of astrophysical environments over cosmic time. For a shallow all-sky survey, we expect to detect over 4 million sources in total intensity > 0.45 mJy beam−1 and over 2.2 105 sources in polarized intensity. With × these new observations, we expect to discover new classes of polarized radio sources in very turbulent astrophysical environments and those with extreme values of Faraday depth. Moreover, by determining reliable -
Dark Energy and Dark Matter
Dark Energy and Dark Matter Jeevan Regmi Department of Physics, Prithvi Narayan Campus, Pokhara [email protected] Abstract: The new discoveries and evidences in the field of astrophysics have explored new area of discussion each day. It provides an inspiration for the search of new laws and symmetries in nature. One of the interesting issues of the decade is the accelerating universe. Though much is known about universe, still a lot of mysteries are present about it. The new concepts of dark energy and dark matter are being explained to answer the mysterious facts. However it unfolds the rays of hope for solving the various properties and dimensions of space. Keywords: dark energy, dark matter, accelerating universe, space-time curvature, cosmological constant, gravitational lensing. 1. INTRODUCTION observations. Precision measurements of the cosmic It was Albert Einstein first to realize that empty microwave background (CMB) have shown that the space is not 'nothing'. Space has amazing properties. total energy density of the universe is very near the Many of which are just beginning to be understood. critical density needed to make the universe flat The first property that Einstein discovered is that it is (i.e. the curvature of space-time, defined in General possible for more space to come into existence. And Relativity, goes to zero on large scales). Since energy his cosmological constant makes a prediction that is equivalent to mass (Special Relativity: E = mc2), empty space can possess its own energy. Theorists this is usually expressed in terms of a critical mass still don't have correct explanation for this but they density needed to make the universe flat. -
Sabine Hossenfelder on “The Case Against Beauty in Physics” Julia
Rationally Speaking #211: Sabine Hossenfelder on “The case against beauty in physics” Julia: Welcome to Rationally Speaking, the podcast where we explore the borderlands between reason and nonsense. I'm your host, Julia Galef, and I'm here with today's guest, Sabine Hossenfelder. Sabine is a theoretical physicist, focusing on quantum gravity. She's a research fellow at the Frankfurt Institute for Advanced Studies, and blogs at Back Reaction. She just published the book, "Lost in Math: How Beauty Leads Physics Astray." "Lost in Math” argues that physicists, in at least certain sub-fields, evaluate theories based heavily on aesthetics, like is this theory beautiful? Instead of simply, what does the evidence suggest is true? The book is full of interviews Sabine did with top physicists, where she tries to ask them: what's the justification for this? Why should we expect beauty to be a good guide to truth? And, spoiler alert, ultimately, she comes away rather unsatisfied with the answers. So, we're going to talk about "Lost in Math" and the case for and against beauty in physics. Sabine, welcome to the show. Sabine: Hello. Julia: So, probably best to start with: what do you mean by beauty, in this context? And is it closer to a kind of “beauty is in the eye of the beholder” thing, like, every physicist has their own sort of aesthetic sense? Or is more like there's a consensus among physicists about what constitutes a beautiful theory? Sabine: Interestingly enough, there's mostly consensus about it. Let me put ahead that I will not try to tell anyone what beauty means, I am just trying to summarize what physicists seem to mean when they speak of beauty, when they say “that theory is beautiful.” There are several ingredients to this sense of beauty. -
Can an Axion Be the Dark Energy Particle?
Kuwait53 J. Sci.Can 45 an(3) axion pp 53-56, be the 2018 dark energy particle? Can an axion be the dark energy particle? Elias C. Vagenas Theoretical Physics Group, Department of Physics Kuwait University, P.O. Box 5969, Safat 13060, Kuwait [email protected] Abstract Following a phenomenological analysis done by the late Martin Perl for the detection of the dark energy, we show that an axion of energy can be a viable candidate for the dark energy particle. In particular, we obtain the characteristic length and frequency of the axion as a quantum particle. Then, employing a relation that connects the energy density with the frequency of a particle, i.e., , we show that the energy density of axions, with the aforesaid value of mass, as obtained from our theoretical analysis is proportional to the dark energy density computed on observational data, i.e., . Keywords: Axion, axion-like particles, dark energy, dark energy particle 1. Introduction Therefore, though the energy density of the electric field, i.e., One of the most important and still unsolved problem in , can be detected and measured, the dark energy density, contemporary physics is related to the energy content of the i.e., , which is much larger has not been detected yet. universe. According to the recent results of the 2015 Planck Of course, one has to avoid to make an experiment for the mission (Ade et al., 2016), the universe roughly consists of detection and measurement of the dark energy near the 69.11% dark energy, 26.03% dark matter, and 4.86% baryonic surface of the Earth, or the Sun, or the planets, since the (ordinary) matter. -
Can Mass Be Negative?
Can Mass Be Negative? Vladik Kreinovich1 and Sergei Soloviev2 1Department of Computer Science University of Texas at El Paso El Paso, TX 7996058, USA [email protected] 2Institut de Recherche en Informatique de Toulouse (IRIT) IRIT, porte 426 118 route de Narbonne 31062 Toulouse cedex 4, France [email protected] Abstract Overcoming the force of gravity is an important part of space travel and a significant obstacle preventing many seemingly reasonable space travel schemes to become practical. Science fiction writers like to imagine materials that may help to make space travel easier. Negative mass { supposedly causing anti-gravity { is one of the popular ideas in this regard. But can mass be negative? In this paper, we show that negative masses are not possible { their existence would enable us to create energy out of nothing, which contradicts to the energy conservation law. 1 Formulation of the Problem Overcoming the force of gravity is an important part of space travel and a significant obstacle preventing many seemingly reasonable space travel schemes to become practical. Science fiction writers like to imagine materials that may help to make space travel easier. Negative mass { supposedly causing anti- gravity { is one of the popular ideas in this regard. But can mass be negative? 2 Reminder: There Are Different Types of Masses To properly answer the question of whether negative masses are possible, it is important to take into account that there are, in principle, three types of masses: 1 • inertial mass mI that describes how an object reacts to a force F : the object's acceleration a is determined by Newton's law mI · a = F ; and • active and passive gravitational mass mA and mP : gravitation force ex- erted by Object 1 with active mass m on Object 2 with passive mass m · m A1 m is equal to F = G · A1 P 2 ; where r is the distance between the P 2 r2 two objects; see, e.g., [1, 3]. -
Dark Energy and CMB
Dark Energy and CMB Conveners: S. Dodelson and K. Honscheid Topical Conveners: K. Abazajian, J. Carlstrom, D. Huterer, B. Jain, A. Kim, D. Kirkby, A. Lee, N. Padmanabhan, J. Rhodes, D. Weinberg Abstract The American Physical Society's Division of Particles and Fields initiated a long-term planning exercise over 2012-13, with the goal of developing the community's long term aspirations. The sub-group \Dark Energy and CMB" prepared a series of papers explaining and highlighting the physics that will be studied with large galaxy surveys and cosmic microwave background experiments. This paper summarizes the findings of the other papers, all of which have been submitted jointly to the arXiv. arXiv:1309.5386v2 [astro-ph.CO] 24 Sep 2013 2 1 Cosmology and New Physics Maps of the Universe when it was 400,000 years old from observations of the cosmic microwave background and over the last ten billion years from galaxy surveys point to a compelling cosmological model. This model requires a very early epoch of accelerated expansion, inflation, during which the seeds of structure were planted via quantum mechanical fluctuations. These seeds began to grow via gravitational instability during the epoch in which dark matter dominated the energy density of the universe, transforming small perturbations laid down during inflation into nonlinear structures such as million light-year sized clusters, galaxies, stars, planets, and people. Over the past few billion years, we have entered a new phase, during which the expansion of the Universe is accelerating presumably driven by yet another substance, dark energy. Cosmologists have historically turned to fundamental physics to understand the early Universe, successfully explaining phenomena as diverse as the formation of the light elements, the process of electron-positron annihilation, and the production of cosmic neutrinos. -
Negative Matter, Repulsion Force, Dark Matter, Phantom And
Negative Matter, Repulsion Force, Dark Matter, Phantom and Theoretical Test Their Relations with Inflation Cosmos and Higgs Mechanism Yi-Fang Chang Department of Physics, Yunnan University, Kunming, 650091, China (e-mail: [email protected]) Abstract: First, dark matter is introduced. Next, the Dirac negative energy state is rediscussed. It is a negative matter with some new characteristics, which are mainly the gravitation each other, but the repulsion with all positive matter. Such the positive and negative matters are two regions of topological separation in general case, and the negative matter is invisible. It is the simplest candidate of dark matter, and can explain some characteristics of the dark matter and dark energy. Recent phantom on dark energy is namely a negative matter. We propose that in quantum fluctuations the positive matter and negative matter are created at the same time, and derive an inflation cosmos, which is created from nothing. The Higgs mechanism is possibly a product of positive and negative matter. Based on a basic axiom and the two foundational principles of the negative matter, we research its predictions and possible theoretical tests, in particular, the season effect. The negative matter should be a necessary development of Dirac theory. Finally, we propose the three basic laws of the negative matter. The existence of four matters on positive, opposite, and negative, negative-opposite particles will form the most perfect symmetrical world. Key words: dark matter, negative matter, dark energy, phantom, repulsive force, test, Dirac sea, inflation cosmos, Higgs mechanism. 1. Introduction The speed of an object surrounded a galaxy is measured, which can estimate mass of the galaxy.