A Unifying Theory of Dark Energy and Dark Matter: Negative Masses and Matter Creation Within a Modified ΛCDM Framework?,?? J
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Arxiv:1904.10313V3 [Gr-Qc] 22 Oct 2020 PACS Numbers: Keywords: Entropy, Holographic Principle and CCDM Models
Thermodynamic constraints on matter creation models R. Valentim∗ Departamento de F´ısica, Instituto de Ci^enciasAmbientais, Qu´ımicas e Farmac^euticas - ICAQF, Universidade Federal de S~aoPaulo (UNIFESP) Unidade Jos´eAlencar, Rua S~aoNicolau No. 210, 09913-030 { Diadema, SP, Brazil J. F. Jesusy Universidade Estadual Paulista (UNESP), C^ampusExperimental de Itapeva Rua Geraldo Alckmin 519, 18409-010, Vila N. Sra. de F´atima,Itapeva, SP, Brazil and Universidade Estadual Paulista (UNESP), Faculdade de Engenharia de Guaratinguet´a Departamento de F´ısica e Qu´ımica, Av. Dr. Ariberto Pereira da Cunha 333, 12516-410 - Guaratinguet´a,SP, Brazil Abstract Entropy is a fundamental concept from Thermodynamics and it can be used to study models on context of Creation Cold Dark Matter (CCDM). From conditions on the first (S_ 0)1 and ≥ second order (S¨ < 0) time derivatives of total entropy in the initial expansion of Sitter through the radiation and matter eras until the end of Sitter expansion, it is possible to estimate the intervals of parameters. The total entropy (St) is calculated as sum of the entropy at all eras (Sγ and Sm) plus the entropy of the event horizon (Sh). This term derives from the Holographic Principle where it suggests that all information is contained on the observable horizon. The main feature of this method for these models are that thermodynamic equilibrium is reached in a final de Sitter era. Total entropy of the universe is calculated with three terms: apparent horizon (Sh), entropy of matter (Sm) and entropy of radiation (Sγ). This analysis allows to estimate intervals of parameters of CCDM models. -
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. -
European Astroparticle Physics Strategy 2017-2026 Astroparticle Physics European Consortium
European Astroparticle Physics Strategy 2017-2026 Astroparticle Physics European Consortium August 2017 European Astroparticle Physics Strategy 2017-2026 www.appec.org Executive Summary Astroparticle physics is the fascinating field of research long-standing mysteries such as the true nature of Dark at the intersection of astronomy, particle physics and Matter and Dark Energy, the intricacies of neutrinos cosmology. It simultaneously addresses challenging and the occurrence (or non-occurrence) of proton questions relating to the micro-cosmos (the world decay. of elementary particles and their fundamental interactions) and the macro-cosmos (the world of The field of astroparticle physics has quickly celestial objects and their evolution) and, as a result, established itself as an extremely successful endeavour. is well-placed to advance our understanding of the Since 2001 four Nobel Prizes (2002, 2006, 2011 and Universe beyond the Standard Model of particle physics 2015) have been awarded to astroparticle physics and and the Big Bang Model of cosmology. the recent – revolutionary – first direct detections of gravitational waves is literally opening an entirely new One of its paths is targeted at a better understanding and exhilarating window onto our Universe. We look of cataclysmic events such as: supernovas – the titanic forward to an equally exciting and productive future. explosions marking the final evolutionary stage of massive stars; mergers of multi-solar-mass black-hole Many of the next generation of astroparticle physics or neutron-star binaries; and, most compelling of all, research infrastructures require substantial capital the violent birth and subsequent evolution of our infant investment and, for Europe to remain competitive Universe. -
Wimps and Machos ENCYCLOPEDIA of ASTRONOMY and ASTROPHYSICS
WIMPs and MACHOs ENCYCLOPEDIA OF ASTRONOMY AND ASTROPHYSICS WIMPs and MACHOs objects that could be the dark matter and still escape detection. For example, if the Galactic halo were filled –3 . WIMP is an acronym for weakly interacting massive par- with Jupiter mass objects (10 Mo) they would not have ticle and MACHO is an acronym for massive (astrophys- been detected by emission or absorption of light. Brown . ical) compact halo object. WIMPs and MACHOs are two dwarf stars with masses below 0.08Mo or the black hole of the most popular DARK MATTER candidates. They repre- remnants of an early generation of stars would be simi- sent two very different but reasonable possibilities of larly invisible. Thus these objects are examples of what the dominant component of the universe may be. MACHOs. Other examples of this class of dark matter It is well established that somewhere between 90% candidates include primordial black holes created during and 99% of the material in the universe is in some as yet the big bang, neutron stars, white dwarf stars and vari- undiscovered form. This material is the gravitational ous exotic stable configurations of quantum fields, such glue that holds together galaxies and clusters of galaxies as non-topological solitons. and plays an important role in the history and fate of the An important difference between WIMPs and universe. Yet this material has not been directly detected. MACHOs is that WIMPs are non-baryonic and Since extensive searches have been done, this means that MACHOS are typically (but not always) formed from this mysterious material must not emit or absorb appre- baryonic material. -
GURPS4E Ultra-Tech.Qxp
Written by DAVID PULVER, with KENNETH PETERS Additional Material by WILLIAM BARTON, LOYD BLANKENSHIP, and STEVE JACKSON Edited by CHRISTOPHER AYLOTT, STEVE JACKSON, SEAN PUNCH, WIL UPCHURCH, and NIKOLA VRTIS Cover Art by SIMON LISSAMAN, DREW MORROW, BOB STEVLIC, and JOHN ZELEZNIK Illustrated by JESSE DEGRAFF, IGOR FIORENTINI, SIMON LISSAMAN, DREW MORROW, E. JON NETHERLAND, AARON PANAGOS, CHRISTOPHER SHY, BOB STEVLIC, and JOHN ZELEZNIK Stock # 31-0104 Version 1.0 – May 22, 2007 STEVE JACKSON GAMES CONTENTS INTRODUCTION . 4 Adjusting for SM . 16 PERSONAL GEAR AND About the Authors . 4 EQUIPMENT STATISTICS . 16 CONSUMER GOODS . 38 About GURPS . 4 Personal Items . 38 2. CORE TECHNOLOGIES . 18 Clothing . 38 1. ULTRA-TECHNOLOGY . 5 POWER . 18 Entertainment . 40 AGES OF TECHNOLOGY . 6 Power Cells. 18 Recreation and TL9 – The Microtech Age . 6 Generators . 20 Personal Robots. 41 TL10 – The Robotic Age . 6 Energy Collection . 20 TL11 – The Age of Beamed and 3. COMMUNICATIONS, SENSORS, Exotic Matter . 7 Broadcast Power . 21 AND MEDIA . 42 TL12 – The Age of Miracles . 7 Civilization and Power . 21 COMMUNICATION AND INTERFACE . 42 Even Higher TLs. 7 COMPUTERS . 21 Communicators. 43 TECH LEVEL . 8 Hardware . 21 Encryption . 46 Technological Progression . 8 AI: Hardware or Software? . 23 Receive-Only or TECHNOLOGY PATHS . 8 Software . 24 Transmit-Only Comms. 46 Conservative Hard SF. 9 Using a HUD . 24 Translators . 47 Radical Hard SF . 9 Ubiquitous Computing . 25 Neural Interfaces. 48 CyberPunk . 9 ROBOTS AND TOTAL CYBORGS . 26 Networks . 49 Nanotech Revolution . 9 Digital Intelligences. 26 Mail and Freight . 50 Unlimited Technology. 9 Drones . 26 MEDIA AND EDUCATION . 51 Emergent Superscience . -
Dark Matter and the Early Universe: a Review Arxiv:2104.11488V1 [Hep-Ph
Dark matter and the early Universe: a review A. Arbey and F. Mahmoudi Univ Lyon, Univ Claude Bernard Lyon 1, CNRS/IN2P3, Institut de Physique des 2 Infinis de Lyon, UMR 5822, 69622 Villeurbanne, France Theoretical Physics Department, CERN, CH-1211 Geneva 23, Switzerland Institut Universitaire de France, 103 boulevard Saint-Michel, 75005 Paris, France Abstract Dark matter represents currently an outstanding problem in both cosmology and particle physics. In this review we discuss the possible explanations for dark matter and the experimental observables which can eventually lead to the discovery of dark matter and its nature, and demonstrate the close interplay between the cosmological properties of the early Universe and the observables used to constrain dark matter models in the context of new physics beyond the Standard Model. arXiv:2104.11488v1 [hep-ph] 23 Apr 2021 1 Contents 1 Introduction 3 2 Standard Cosmological Model 3 2.1 Friedmann-Lema^ıtre-Robertson-Walker model . 4 2.2 A quick story of the Universe . 5 2.3 Big-Bang nucleosynthesis . 8 3 Dark matter(s) 9 3.1 Observational evidences . 9 3.1.1 Galaxies . 9 3.1.2 Galaxy clusters . 10 3.1.3 Large and cosmological scales . 12 3.2 Generic types of dark matter . 14 4 Beyond the standard cosmological model 16 4.1 Dark energy . 17 4.2 Inflation and reheating . 19 4.3 Other models . 20 4.4 Phase transitions . 21 5 Dark matter in particle physics 21 5.1 Dark matter and new physics . 22 5.1.1 Thermal relics . 22 5.1.2 Non-thermal relics . -
The State of the Multiverse: the String Landscape, the Cosmological Constant, and the Arrow of Time
The State of the Multiverse: The String Landscape, the Cosmological Constant, and the Arrow of Time Raphael Bousso Center for Theoretical Physics University of California, Berkeley Stephen Hawking: 70th Birthday Conference Cambridge, 6 January 2011 RB & Polchinski, hep-th/0004134; RB, arXiv:1112.3341 The Cosmological Constant Problem The Landscape of String Theory Cosmology: Eternal inflation and the Multiverse The Observed Arrow of Time The Arrow of Time in Monovacuous Theories A Landscape with Two Vacua A Landscape with Four Vacua The String Landscape Magnitude of contributions to the vacuum energy graviton (a) (b) I Vacuum fluctuations: SUSY cutoff: ! 10−64; Planck scale cutoff: ! 1 I Effective potentials for scalars: Electroweak symmetry breaking lowers Λ by approximately (200 GeV)4 ≈ 10−67. The cosmological constant problem −121 I Each known contribution is much larger than 10 (the observational upper bound on jΛj known for decades) I Different contributions can cancel against each other or against ΛEinstein. I But why would they do so to a precision better than 10−121? Why is the vacuum energy so small? 6= 0 Why is the energy of the vacuum so small, and why is it comparable to the matter density in the present era? Recent observations Supernovae/CMB/ Large Scale Structure: Λ ≈ 0:4 × 10−121 Recent observations Supernovae/CMB/ Large Scale Structure: Λ ≈ 0:4 × 10−121 6= 0 Why is the energy of the vacuum so small, and why is it comparable to the matter density in the present era? The Cosmological Constant Problem The Landscape of String Theory Cosmology: Eternal inflation and the Multiverse The Observed Arrow of Time The Arrow of Time in Monovacuous Theories A Landscape with Two Vacua A Landscape with Four Vacua The String Landscape Many ways to make empty space Topology and combinatorics RB & Polchinski (2000) I A six-dimensional manifold contains hundreds of topological cycles. -
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 -
Engineering the Quantum Foam
Engineering the Quantum Foam Reginald T. Cahill School of Chemistry, Physics and Earth Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia [email protected] _____________________________________________________ ABSTRACT In 1990 Alcubierre, within the General Relativity model for space-time, proposed a scenario for ‘warp drive’ faster than light travel, in which objects would achieve such speeds by actually being stationary within a bubble of space which itself was moving through space, the idea being that the speed of the bubble was not itself limited by the speed of light. However that scenario required exotic matter to stabilise the boundary of the bubble. Here that proposal is re-examined within the context of the new modelling of space in which space is a quantum system, viz a quantum foam, with on-going classicalisation. This model has lead to the resolution of a number of longstanding problems, including a dynamical explanation for the so-called `dark matter’ effect. It has also given the first evidence of quantum gravity effects, as experimental data has shown that a new dimensionless constant characterising the self-interaction of space is the fine structure constant. The studies here begin the task of examining to what extent the new spatial self-interaction dynamics can play a role in stabilising the boundary without exotic matter, and whether the boundary stabilisation dynamics can be engineered; this would amount to quantum gravity engineering. 1 Introduction The modelling of space within physics has been an enormously challenging task dating back in the modern era to Galileo, mainly because it has proven very difficult, both conceptually and experimentally, to get a ‘handle’ on the phenomenon of space.