Modified Newtonian Dynamics (MOND): Observational Phenomenology and Relativistic Extensions Benoit Famaey, Stacy S
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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. -
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. -
Analysis and Instrumentation for a Xenon-Doped Liquid Argon System
Analysis and instrumentation for a xenon-doped liquid argon system Ryan Gibbons Work completed under the advisement of Professor Michael Gold Department of Physics and Astronomy The University of New Mexico May 27, 2020 1 Abstract Liquid argon is a scintillator frequently used in neutrino and dark matter exper- iments. In particular, is the upcoming LEGEND experiment, a neutrinoless double beta decay search, which will utilize liquid argon as an active veto system. Neutri- noless double beta decay is a theorized lepton number violating process that is only possible if neutrinos are Majorana in nature. To achieve the LEGEND background goal, the liquid argon veto must be more efficient. Past studies have shown the ad- dition of xenon in quantities of parts-per-million in liquid argon improves the light yield, and therefore efficiency, of such a system. Further work, however, is needed to fully understand the effects of this xenon doping. I present a physical model for the light intensity of xenon-doped liquid argon. This model is fitted to data from various xenon concentrations from BACoN, a liquid argon test stand. Additionally, I present preliminary work on the instrumentation of silicon photomultipliers for BACoN. 2 Contents 1 Introduction 4 1.1 Neutrinos and double beta decay . 4 1.2 LEGEND and BACoN . 5 1.3 Liquid argon . 6 2 Physical modeling of xenon-doped liquid argon 8 2.1 Model . 8 2.2 Fits to BACoN Data . 9 2.3 Analysis of Rate Constant . 12 3 Instrumentation of SiPMs 12 4 Conclusions and Future Work 13 3 1 Introduction 1.1 Neutrinos and double beta decay Neutrinos are neutral leptons that come in three flavors: electron, muon, and tao. -
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 . -
Adrien Christian René THOB
THE RELATIONSHIP BETWEEN THE MORPHOLOGY AND KINEMATICS OF GALAXIES AND ITS DEPENDENCE ON DARK MATTER HALO STRUCTURE IN SIMULATED GALAXIES Adrien Christian René THOB A thesis submitted in partial fulfilment of the requirements of Liverpool John Moores University for the degree of Doctor of Philosophy. 26 April 2019 To my grand-parents, René Roumeaux, Christian Thob, Yvette Roumeaux (née Bajaud) and Anne-Marie Thob (née Léglise). ii Abstract Galaxies are among nature’s most majestic and diverse structures. They can play host to as few as several thousands of stars, or as many as hundreds of billions. They exhibit a broad range of shapes, sizes, colours, and they can inhabit vastly differing cosmic environments. The physics of galaxy formation is highly non-linear and in- volves a variety of physical mechanisms, precluding the development of entirely an- alytic descriptions, thus requiring that theoretical ideas concerning the origin of this diversity are tested via the confrontation of numerical models (or “simulations”) with observational measurements. The EAGLE project (which stands for Evolution and Assembly of GaLaxies and their Environments) is a state-of-the-art suite of such cos- mological hydrodynamical simulations of the Universe. EAGLE is unique in that the ill-understood efficiencies of feedback mechanisms implemented in the model were calibrated to ensure that the observed stellar masses and sizes of present-day galaxies were reproduced. We investigate the connection between the morphology and internal 9:5 kinematics of the stellar component of central galaxies with mass M? > 10 M in the EAGLE simulations. We compare several kinematic diagnostics commonly used to describe simulated galaxies, and find good consistency between them. -
Particle Dark Matter an Introduction Into Evidence, Models, and Direct Searches
Particle Dark Matter An Introduction into Evidence, Models, and Direct Searches Lecture for ESIPAP 2016 European School of Instrumentation in Particle & Astroparticle Physics Archamps Technopole XENON1T January 25th, 2016 Uwe Oberlack Institute of Physics & PRISMA Cluster of Excellence Johannes Gutenberg University Mainz http://xenon.physik.uni-mainz.de Outline ● Evidence for Dark Matter: ▸ The Problem of Missing Mass ▸ In galaxies ▸ In galaxy clusters ▸ In the universe as a whole ● DM Candidates: ▸ The DM particle zoo ▸ WIMPs ● DM Direct Searches: ▸ Detection principle, physics inputs ▸ Example experiments & results ▸ Outlook Uwe Oberlack ESIPAP 2016 2 Types of Evidences for Dark Matter ● Kinematic studies use luminous astrophysical objects to probe the gravitational potential of a massive environment, e.g.: ▸ Stars or gas clouds probing the gravitational potential of galaxies ▸ Galaxies or intergalactic gas probing the gravitational potential of galaxy clusters ● Gravitational lensing is an independent way to measure the total mass (profle) of a foreground object using the light of background sources (galaxies, active galactic nuclei). ● Comparison of mass profles with observed luminosity profles lead to a problem of missing mass, usually interpreted as evidence for Dark Matter. ● Measuring the geometry (curvature) of the universe, indicates a ”fat” universe with close to critical density. Comparison with luminous mass: → a major accounting problem! Including observations of the expansion history lead to the Standard Model of Cosmology: accounting defcit solved by ~68% Dark Energy, ~27% Dark Matter and <5% “regular” (baryonic) matter. ● Other lines of evidence probe properties of matter under the infuence of gravity: ▸ the equation of state of oscillating matter as observed through fuctuations of the Cosmic Microwave Background (acoustic peaks). -
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. -
DARK MATTER and NEUTRINOS Arxiv:1711.10564V1 [Physics.Pop-Ph]
Physics Education 1 dateline DARK MATTER AND NEUTRINOS Gazal Sharma1, Anu2 and B. C. Chauhan3 Department of Physics & Astronomical Science School of Physical & Material Sciences Central University of Himachal Pradesh (CUHP) Dharamshala, Kangra (HP) INDIA-176215. [email protected] [email protected] [email protected] (Submitted 03-08-2015) Abstract The Keplerian distribution of velocities is not observed in the rotation of large scale structures, such as found in the rotation of spiral galaxies. The deviation from Keplerian distribution provides compelling evidence of the presence of non-luminous matter i.e. called dark matter. There are several astrophysical motivations for investigating the dark matter in and around the galaxy as halo. In this work we address various theoretical and experimental indications pointing towards the existence of this unknown form of matter. Amongst its constituents neutrino is one of the most prospective candidates. We know the neutrinos oscillate and have tiny masses, but there are also signatures for existence of heavy and light sterile neutrinos and possibility of their mixing. Altogether, the role of neutrinos is of great interests in cosmology and understanding dark matter. arXiv:1711.10564v1 [physics.pop-ph] 23 Nov 2017 1 Introduction revealed in 2013 that our Universe contains 68:3% of dark energy, 26:8% of dark matter, and only 4:9% of the Universe is known mat- As a human being the biggest surprise for us ter which includes all the stars, planetary sys- was, that the Universe in which we live in tems, galaxies, and interstellar gas etc.. This is mostly dark. -
A Critique of Covariant Emergent Gravity
Prepared for submission to JCAP A Critique of Covariant Emergent Gravity Kirill Zatrimaylov Scuola Normale Superiore and I.N.F.N. Piazza dei Cavalieri 7, 56126, Pisa, Italy E-mail: [email protected] Abstract. I address some problems encountered in the formulation of relativistic models encompassing the MOND phenomenology of radial acceleration. I explore scalar and vector theories with fractional kinetic terms and f(R)-type gravity, demanding that the energy density be bounded from below and that superluminal modes be absent, but also that some consistency constraints with observational results hold. I identify configurations whose energy is unbounded from below and formulate some no-go statements for vector field models and arXiv:2003.10410v1 [gr-qc] 23 Mar 2020 modified gravity theories. Finally, I discuss superfluid dark matter as a hybrid theory lying between CDM and modified gravity, highlighting some difficulties present also in this case, which appears preferable to the others. Contents 1 Introduction1 2 A Brief Overview of MOND3 3 Covariant Theories with Fractional Kinetic Terms6 3.1 Scalar 8 3.2 Vector 9 3.3 Tensor 15 4 Fractional Kinetic Terms from Spontaneous Symmetry Breaking 19 5 Conclusions 20 1 Introduction MOND (Modified Newtonian dynamics), proposed by M. Milgrom in 1981 [1], was meant originally as an alternative to the cold dark matter paradigm: it aims to explain phenomena usually attributed to dark matter via Newtonian laws (either the law of gravity or the law of inertia) that are modified at large distances and small accelerations. Until recently, its actual significance has been somewhat obscure, since it does account for one class of observations (galaxy rotation curves) without addressing other key issues (CMB, primordial structure formation, and displacement between luminous and dark matter components in galaxy cluster collisions). -
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. -
ANTIMATTER a Review of Its Role in the Universe and Its Applications
A review of its role in the ANTIMATTER universe and its applications THE DISCOVERY OF NATURE’S SYMMETRIES ntimatter plays an intrinsic role in our Aunderstanding of the subatomic world THE UNIVERSE THROUGH THE LOOKING-GLASS C.D. Anderson, Anderson, Emilio VisualSegrè Archives C.D. The beginning of the 20th century or vice versa, it absorbed or emitted saw a cascade of brilliant insights into quanta of electromagnetic radiation the nature of matter and energy. The of definite energy, giving rise to a first was Max Planck’s realisation that characteristic spectrum of bright or energy (in the form of electromagnetic dark lines at specific wavelengths. radiation i.e. light) had discrete values The Austrian physicist, Erwin – it was quantised. The second was Schrödinger laid down a more precise that energy and mass were equivalent, mathematical formulation of this as described by Einstein’s special behaviour based on wave theory and theory of relativity and his iconic probability – quantum mechanics. The first image of a positron track found in cosmic rays equation, E = mc2, where c is the The Schrödinger wave equation could speed of light in a vacuum; the theory predict the spectrum of the simplest or positron; when an electron also predicted that objects behave atom, hydrogen, which consists of met a positron, they would annihilate somewhat differently when moving a single electron orbiting a positive according to Einstein’s equation, proton. However, the spectrum generating two gamma rays in the featured additional lines that were not process. The concept of antimatter explained. In 1928, the British physicist was born. -
Ten Years of PAMELA in Space
Ten Years of PAMELA in Space The PAMELA collaboration O. Adriani(1)(2), G. C. Barbarino(3)(4), G. A. Bazilevskaya(5), R. Bellotti(6)(7), M. Boezio(8), E. A. Bogomolov(9), M. Bongi(1)(2), V. Bonvicini(8), S. Bottai(2), A. Bruno(6)(7), F. Cafagna(7), D. Campana(4), P. Carlson(10), M. Casolino(11)(12), G. Castellini(13), C. De Santis(11), V. Di Felice(11)(14), A. M. Galper(15), A. V. Karelin(15), S. V. Koldashov(15), S. Koldobskiy(15), S. Y. Krutkov(9), A. N. Kvashnin(5), A. Leonov(15), V. Malakhov(15), L. Marcelli(11), M. Martucci(11)(16), A. G. Mayorov(15), W. Menn(17), M. Mergè(11)(16), V. V. Mikhailov(15), E. Mocchiutti(8), A. Monaco(6)(7), R. Munini(8), N. Mori(2), G. Osteria(4), B. Panico(4), P. Papini(2), M. Pearce(10), P. Picozza(11)(16), M. Ricci(18), S. B. Ricciarini(2)(13), M. Simon(17), R. Sparvoli(11)(16), P. Spillantini(1)(2), Y. I. Stozhkov(5), A. Vacchi(8)(19), E. Vannuccini(1), G. Vasilyev(9), S. A. Voronov(15), Y. T. Yurkin(15), G. Zampa(8) and N. Zampa(8) (1) University of Florence, Department of Physics, I-50019 Sesto Fiorentino, Florence, Italy (2) INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence, Italy (3) University of Naples “Federico II”, Department of Physics, I-80126 Naples, Italy (4) INFN, Sezione di Naples, I-80126 Naples, Italy (5) Lebedev Physical Institute, RU-119991 Moscow, Russia (6) University of Bari, I-70126 Bari, Italy (7) INFN, Sezione di Bari, I-70126 Bari, Italy (8) INFN, Sezione di Trieste, I-34149 Trieste, Italy (9) Ioffe Physical Technical Institute, RU-194021 St.