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Arxiv:1803.02804V1 [Hep-Ph] 7 Mar 2018 It Must Have Some Rather Specific Characteristics
FERMILAB-PUB-18-066-A Severely Constraining Dark Matter Interpretations of the 21-cm Anomaly Asher Berlina,∗ Dan Hooperb;c;d,y Gordan Krnjaicb,z and Samuel D. McDermottbx aSLAC National Accelerator Laboratory, Menlo Park CA, 94025, USA bFermi National Accelerator Laboratory, Theoretical Astrophysics Group, Batavia, IL, USA cUniversity of Chicago, Kavli Institute for Cosmological Physics, Chicago IL, USA and dUniversity of Chicago, Department of Astronomy and Astrophysics, Chicago IL, USA (Dated: March 8, 2018) The EDGES Collaboration has recently reported the detection of a stronger-than-expected ab- sorption feature in the global 21-cm spectrum, centered at a frequency corresponding to a redshift of z ∼ 17. This observation has been interpreted as evidence that the gas was cooled during this era as a result of scattering with dark matter. In this study, we explore this possibility, applying constraints from the cosmic microwave background, light element abundances, Supernova 1987A, and a variety of laboratory experiments. After taking these constraints into account, we find that the vast majority of the parameter space capable of generating the observed 21-cm signal is ruled out. The only range of models that remains viable is that in which a small fraction, ∼ 0:3 − 2%, of the dark matter consists of particles with a mass of ∼ 10 − 80 MeV and which couple to the photon through a small electric charge, ∼ 10−6 −10−4. Furthermore, in order to avoid being overproduced in the early universe, such models must be supplemented with an additional depletion mechanism, such as annihilations through a Lµ − Lτ gauge boson or annihilations to a pair of rapidly decaying hidden sector scalars. -
Report from the Dark Energy Task Force (DETF)
Fermi National Accelerator Laboratory Fermilab Particle Astrophysics Center P.O.Box 500 - MS209 Batavia, Il l i noi s • 60510 June 6, 2006 Dr. Garth Illingworth Chair, Astronomy and Astrophysics Advisory Committee Dr. Mel Shochet Chair, High Energy Physics Advisory Panel Dear Garth, Dear Mel, I am pleased to transmit to you the report of the Dark Energy Task Force. The report is a comprehensive study of the dark energy issue, perhaps the most compelling of all outstanding problems in physical science. In the Report, we outline the crucial need for a vigorous program to explore dark energy as fully as possible since it challenges our understanding of fundamental physical laws and the nature of the cosmos. We recommend that program elements include 1. Prompt critical evaluation of the benefits, costs, and risks of proposed long-term projects. 2. Commitment to a program combining observational techniques from one or more of these projects that will lead to a dramatic improvement in our understanding of dark energy. (A quantitative measure for that improvement is presented in the report.) 3. Immediately expanded support for long-term projects judged to be the most promising components of the long-term program. 4. Expanded support for ancillary measurements required for the long-term program and for projects that will improve our understanding and reduction of the dominant systematic measurement errors. 5. An immediate start for nearer term projects designed to advance our knowledge of dark energy and to develop the observational and analytical techniques that will be needed for the long-term program. Sincerely yours, on behalf of the Dark Energy Task Force, Edward Kolb Director, Particle Astrophysics Center Fermi National Accelerator Laboratory Professor of Astronomy and Astrophysics The University of Chicago REPORT OF THE DARK ENERGY TASK FORCE Dark energy appears to be the dominant component of the physical Universe, yet there is no persuasive theoretical explanation for its existence or magnitude. -
String Theory, QCD and Black Holes
Black Hole Microstate Structure Fuzzballs and Firewalls Iosif Bena IPhT, CEAEA Saclay with Nick Warner, Jan deBoer, Micha Berkooz, Simon Ross, Gianguido Dall’Agata, Stefano Giusto, Masaki Shigemori, Dieter van den Bleeken, Monica Guica, Sheer El-Showk, Stanislav Kuperstein, Hagen Triendl, Bert Vercnocke, Andrea Puhm, Ref. Ares(2012)790792 - 29/06/2012 ! Department C "Grant Management" ! Mittwoch, 12. März 2014 ! Subject: Aggressive marketing from publishing houses Dear Madam, Dear Sir, The European Research Council Executive Agency (ERCEA) would like to alert you of publishing houses and online publications which try to make profit out of publishing articles, or interviewing researchers funded from the EU budget, either by the European Research Council (ERC) or by the European Commission (EC). From time to time participants in projects funded under the EU framework programmes are contacted – often by telephone - by organisations seeking payment in return for publishing information on the work being undertaken within their projects. As with "cold calling" in general, the claims and assertions made should be treated with an appropriate level of caution before a decision is made on the best course of action. These publications and their services have not been endorsed by the EC, or the ERCEA. Common tactics to secure business may include vague references to high-level contributions from decision makers, or making the project participant believe that his or her activities have been identified on the basis of special merit which may not be the case. Commercial entities use many ways of promoting their services, but grant-holders are not obliged to use them. Whatever the impression given by such service providers, their products have not received any formal approval or endorsement from the EC or the ERCEA. -
Exotic Compact Objects Interacting with Fundamental Fields Engineering
Exotic compact objects interacting with fundamental fields Nuno André Moreira Santos Thesis to obtain the Master of Science Degree in Engineering Physics Supervisors: Prof. Dr. Carlos Alberto Ruivo Herdeiro Prof. Dr. Vítor Manuel dos Santos Cardoso Examination Committee Chairperson: Prof. Dr. José Pizarro de Sande e Lemos Supervisor: Prof. Dr. Carlos Alberto Ruivo Herdeiro Member of the Committee: Dr. Miguel Rodrigues Zilhão Nogueira October 2018 Resumo A astronomia de ondas gravitacionais apresenta-se como uma nova forma de testar os fundamentos da física − e, em particular, a gravidade. Os detetores de ondas gravitacionais por interferometria laser permitirão compreender melhor ou até esclarecer questões de longa data que continuam por responder, como seja a existência de buracos negros. Pese embora o número cumulativo de argumentos teóricos e evidências observacionais que tem vindo a fortalecer a hipótese da sua existência, não há ainda qualquer prova conclusiva. Os dados atualmente disponíveis não descartam a possibilidade de outros objetos exóticos, que não buracos negros, se formarem em resultado do colapso gravitacional de uma estrela suficientemente massiva. De facto, acredita-se que a assinatura do objeto exótico remanescente da coalescência de um sistema binário de objetos compactos pode estar encriptada na amplitude da onda gravitacional emitida durante a fase de oscilações amortecidas, o que tornaria possível a distinção entre buracos negros e outros objetos exóticos. Esta dissertação explora aspetos clássicos da fenomenologia de perturbações escalares e eletromagnéticas de duas famílias de objetos exóticos cuja geometria, apesar de semelhante à de um buraco negro de Kerr, é definida por uma superfície refletora, e não por um horizonte de eventos. -
Kinetic Decoupling of Neutralino Dark Matter
RAPID COMMUNICATIONS PHYSICAL REVIEW D, VOLUME 64, 021302͑R͒ Kinetic decoupling of neutralino dark matter Xuelei Chen* Department of Physics, The Ohio State University, 174 West 18th Avenue, Columbus, Ohio 43210 Marc Kamionkowski† California Institute of Technology, Mail Code 130-33, Pasadena, California 91225 Xinmin Zhang‡ Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918-4, Beijing 100039, People’s Republic of China ͑Received 27 March 2001; published 25 June 2001͒ After neutralinos cease annihilating in the early Universe, they may still scatter elastically from other particles in the primordial plasma. At some point in time, however, they will eventually stop scattering. We calculate the cross sections for neutralino elastic scattering from standard-model particles to determine the time at which this kinetic decoupling occurs. We show that kinetic decoupling occurs above a temperature T ϳMeV. Thereafter, neutralinos act as collisionless cold dark matter. DOI: 10.1103/PhysRevD.64.021302 PACS number͑s͒: 98.80.Cq, 13.15.ϩg, 12.60.Jv, 95.35.ϩd I. INTRODUCTION matter candidates, Gunn et al. ͓6͔ showed that they would fall out of kinetic equilibrium shortly after their annihilation Neutralinos provide perhaps the most promising candidate freezes out. Later, Schmid et al. ͓7͔ estimated the decoupling for the mysterious dark matter in galactic halos ͑see, e.g., temperature of neutralino-neutrino interaction. In this paper Refs. ͓1,2͔ for reviews͒. Such particles would have existed in we consider the process of kinetic decoupling of neutralinos thermal equilibrium in the early Universe when the tempera- in more detail. We calculate the cross sections for elastic ture exceeded the mass of the particle. -
SNOWMASS21-TF1 TF0-057.Pdf 409.50KB 2020-08-31 21:46:42
Snowmass2021 - Letter of Interest Peering inside Black Holes with Gravitational Waves Thematic Areas: (TF01) String theory, quantum gravity, black holes (TF2) Effective field theory techniques (TF3) CFT and formal QFT (TF4) Scattering amplitudes (TF5) Lattice gauge theory (TF6) Theory techniques for precision physics (TF7) Collider phenomenology (TF8) BSM model building (TF9) Astro-particle physics & cosmology (TF10) Quantum Information Science (TF11) Theory of neutrino physics (CF6) Dark Energy and Cosmic Acceleration: Complementarity of Probes and New Facilities (CF7) Cosmic Probes of Fundamental Physics Contact Information: Emil Mottola (Los Alamos National Laboratory & Perimeter Institute)[[email protected]] Author: Emil Mottola Abstract: In classical General Relativity (GR) the interiors of Black Holes (BHs) are not only singular but, if rotating, also admit closed timelike curves, violating causality.1 This feature occurs at macroscopic distance scales, far larger than the microscopic Planck scale LP l. When quantum effects are considered, severe conflicts with statistical thermodynamics, conservation of probability and an enormous BH entropy arise also at the macroscopic horizon scale.2,3 This suggests that a low energy semi-classical Effective Field Theory (EFT) approach should be applicable. In this LOI such an approach based the conformal anomaly is proposed, which leads to a non-singular horizonless, but ultra-compact object called a gravitational condensate star. The gravastar hypothesis can be tested by searching for discrete surface modes and GW echoes emitted after binary merger events. In this new era of GW and multi-messenger astronomy with additional GW detectors coming online in this decade, the time is now ripe for a full-fledged effort to confront these theoretical ideas with the observational data that hold the promise of resolving the conundrum that BHs pose, and potentially point to a new path to ultimate synthesis of gravitation and quantum theory. -
Arxiv:2010.05354V1 [Gr-Qc] 11 Oct 2020
Black hole or Gravastar? The GW190521 case I. Antoniou1, ∗ 1Department of Physics, University of Ioannina, GR-45110, Ioannina, Greece (Dated: August 31, 2021) The existence of cosmological compact objects with very strong gravity is a prediction of General Relativity and an exact solution of the Einstein equations. These objects are called black holes and recently we had the first observations of them. However, the theory of black hole formation has some disadvantages. In order to avoid these, some scientists suggest the existence of gravastars (gravitation vacuum stars), an alternative stellar model which seems to solve the problems of the black hole theory. In this work we compare black holes and gravastars using a wide range of the literature and we emphasize the properties of gravastars, which are consistent with the current cosmological observations. Also, we propose gravastars as the solution of the ”pair-instability” effect and a possible explanation for the observed masses of the compact objects, before the collapse, from the gravitational signal GW190521, since in the formation of a gravastar there aren’t mass restrictions. PACS numbers: 98.62.Ai, 04.20.Cv, 04.30.-w I. INTRODUCTION black holes, or some other compact object with very strong gravity. Many scientists dispute the One of the most attractive concepts in Gen- existence of black holes because if we take into ac- eral Relativity is the existence and the properties count quantum effects, the gravitational collapse of black holes, a region of spacetime where grav- of objects comes to a halt and furthermore no ity is so strong that nothing, no particles or even event horizon forms [2]. -
FARSIDE Probe Study Final Report
Study Participants List, Disclaimers, and Acknowledgements Study Participants List Principal Authors Jack O. Burns, University of Colorado Boulder Gregg Hallinan, California Institute of Technology Co-Authors Jim Lux, NASA Jet Propulsion Laboratory, California Institute of Andres Romero-Wolf, NASA Jet Propulsion Laboratory, California Technology Institute of Technology Lawrence Teitelbaum, NASA Jet Propulsion Laboratory, California Tzu-Ching Chang, NASA Jet Propulsion Laboratory, California Institute of Technology Institute of Technology Jonathon Kocz, California Institute of Technology Judd Bowman, Arizona State University Robert MacDowall, NASA Goddard Space Flight Center Justin Kasper, University of Michigan Richard Bradley, National Radio Astronomy Observatory Marin Anderson, California Institute of Technology David Rapetti, University of Colorado Boulder Zhongwen Zhen, California Institute of Technology Wenbo Wu, California Institute of Technology Jonathan Pober, Brown University Steven Furlanetto, UCLA Jordan Mirocha, McGill University Alex Austin, NASA Jet Propulsion Laboratory, California Institute of Technology Disclaimers/Acknowledgements Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The cost information contained in this document is of a budgetary and planning nature and is intended for informational purposes only. It does not constitute a commitment on the part of JPL and/or Caltech © 2019. -
Table of Contents (Print)
PHYSICAL REVIEW D PERIODICALS For editorial and subscription correspondence, Postmaster send address changes to: please see inside front cover (ISSN: 1550-7998) APS Subscription Services P.O. Box 41 Annapolis Junction, MD 20701 THIRD SERIES, VOLUME 97, NUMBER 12 CONTENTS D15 JUNE 2018 The Table of Contents is a total listing of Parts A and B. Part A consists of articles 121301–124019, and Part B articles 124020–129903(E) PART A RAPID COMMUNICATIONS Emergent dark energy from dark matter (6 pages) ................................................................................... 121301(R) Takeshi Kobayashi and Pedro G. Ferreira ARTICLES Search for gamma-ray emission from the nearby dwarf spheroidal galaxies with 9 years of Fermi-LAT data (7 pages) 122001 Shang Li, Kai-Kai Duan, Yun-Feng Liang, Zi-Qing Xia, Zhao-Qiang Shen, Xiang Li, Neng-Hui Liao, Lei Feng, Qiang Yuan, Yi-Zhong Fan, and Jin Chang Calibrating the system dynamics of LISA Pathfinder (14 pages) .................................................................. 122002 M. Armano et al. Particle swarm optimization of the sensitivity of a cryogenic gravitational wave detector (12 pages) ...................... 122003 Yuta Michimura, Kentaro Komori, Atsushi Nishizawa, Hiroki Takeda, Koji Nagano, Yutaro Enomoto, Kazuhiro Hayama, Kentaro Somiya, and Masaki Ando Reconstruction of cosmic ray air showers with Tunka-Rex data using template fitting of radio pulses (10 pages) ....... 122004 P. A. Bezyazeekov, N. M. Budnev, D. Chernykh, O. Fedorov, O. A. Gress, A. Haungs, R. Hiller, T. Huege, Y. Kazarina, M. Kleifges, D. Kostunin, E. E. Korosteleva, L. A. Kuzmichev, V. Lenok, N. Lubsandorzhiev, T. Marshalkina, R. R. Mirgazov, R. Monkhoev, E. Osipova, A. Pakhorukov, L. Pankov, V. V. Prosin, F. -
New Views of Cosmology and the Microworld
XXX SLAC Summer Institute (SSI2002), Stanford, CA, 5-16 August, 2002 NEW VIEWS OF COSMOLOGY AND THE MICROWORLD Marc Kamionkowski∗ California Institute of Technology Mail Code 130-33 Pasadena, CA 91125 ABSTRACT The past few years have seen several breakthroughs in particle astrophysics and cosmology. In several cases, new observations can only be explained with the introduction of new fundamental physics. In this talk I summarize some of these recent advances and describe several areas where progress may well be made in the future. More specifically, I focus on supersymmet- ric and axion dark matter, self-interacting dark matter, cosmic-microwave- background and large-scale-structure tests of inflation, and the dark-energy problem. ∗Supported by NASA NAG5-9821 and DoE DE-FG03-92-ER40701. c 2002 by Marc Kamionkowski. TF04 713 XXX SLAC Summer Institute (SSI2002), Stanford, CA, 5-16 August, 2002 1 Introduction The aim of particle physics is to understand the fundamental laws of nature. The primary tools in this endeavor have been and continue to be accelerator experiments which provide controlled environments for precise experiments. However, this avenue may have limitations, especially considering that many of the most promising ideas for new physics beyond the standard model—e.g., grand unification and quantum gravity—can be tested only at energies many orders of magnitude greater than those accessible by current and planned accelerators. We have recently seen an increased effort to develop cosmological and astrophysical tools to search for and/or constrain new physics beyond the standard model. These efforts do have precedents: Newton’s law of universal gravitation was motivated by planetary orbits. -
Dark Matter Astrophysics 3 2.1 Galactic Rotation Curves
Dark Matter Astrophysics Guido D’Amico, Marc Kamionkowski and Kris Sigurdson Abstract These lectures are intended to provide a brief pedagogical review of dark matter for the newcomer to the subject. We begin with a discussion of the astro- physical evidence for dark matter. The standard weakly-interacting massive particle (WIMP) scenario—the motivation, particle models, and detection techniques—is then reviewed. We provide a brief sampling of some recent variations to the stan- dard WIMP scenario as well as some alternatives (axions and sterile neutrinos). Exercises are provided for the reader.1 1 Introduction Dark matter is an essential ingredient in a good fraction of the literature on extra- galactic astronomy and cosmology. Since dark matter cannot be made of any of the usual standard-model particles (as we will discuss below), dark matter is also a cen- tral focus of elementary-particle physics. The purpose of this review is to provide a pedagogical introduction to the principle astrophysical evidence for dark matter and to some of the particle candidates. Rather than present a comprehensive survey of the vast and increasingly precise measurements of the amount and distribution of dark matter, we will present very Guido D’Amico SISSA, via Beirut 2-4, 34014 Trieste, Italy; e-mail: [email protected] Marc Kamionkowski arXiv:0907.1912v1 [astro-ph.CO] 10 Jul 2009 California Institute of Technology, Mail Code 350-17, Pasadena, CA 91125, USA; e-mail: [email protected] Kris Sigurdson Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada; e-mail: [email protected] 1 Based on lectures given by MK at the Villa Olmo School on “The Dark Side of the Universe,” 14–18 May 2007 and by KS at the XIX Heidelberg Physics Graduate Days, 8-12 October 2007. -
Patrick C. Breysse's CV
Patrick C. Breysse Postdoctoral Fellow, Canadian Institute for Theoretical Astrophysics 60 St. George Street, Rm 1302, Toronto, ON Canada M5S 3H8 [email protected] • +1 (647) 534-0268 PROFESSIONAL Canadian Institute for Theoretical Astrophysics, Toronto, ON, Canada HISTORY Postdoctoral Fellow Sep 2017- Present EDUCATION Johns Hopkins University, Baltimore, MD, USA Doctor of Philosophy (Ph.D.) in Physics and Astronomy Jun 2012 – May 2017 • Adviser: Professor Marc Kamionkowski • Research areas: Theoretical cosmology, large scale structure, intensity mapping • Thesis: High-Redshift Astrophysics and Cosmology with Intensity Mapping Master of Arts (M.A.) in Physics and Astronomy Jun 2012 – May 2015 The Pennsylvania State University, University Park, Pennsylvania, USA Bachelor of Science (B.S.) in Physics Bachelor of Science (B.S.) in Astronomy and Astrophysics Aug 2008 – May 2012 • Graduated with Distinction and with Honors in Physics. COLLABORATION Carbon Monoxide Mapping Array Pathfinder (COMAP) MEMBERSHIPS Lead, Science & Modeling Working Group 2018 – Present Cerro Chajnantor Atacama Telescope – PRIME (CCATp) Member, Science Working Group 2018 – Present EXperiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) Member, Science Working Group 2019 – Present SELECTED Participant, 66th Lindau Nobel Laureate Meeting, Jun 2016 AWARDS Max Bodmer Graduate Research Fellowship, Sep 2012 Penn State Astronomy and Astrophysics Student Marshall, May 2012 Astronaut Scholarship, 2011 STUDENTS Anubhav Mathur MENTORED former Univ. of Toronto undergraduate (now grad student at JHU) Henry Liu UBC undergraduate TEACHING Summer Astro 101 Course Summer 2018, 2019 Lecturer CITA cosmology blackboard talks 2017–Present Speaker, 6× CITA pedagogical blackboard talks 2017–present Speaker, 4× General Physics I, JHU Spring 2014 Teaching Assistant Special Relativity and Waves, JHU Fall 2013 Teaching Assistant Page 1 of 4 PROFESSIONAL CITA Cosmology Discussion Group SERVICE Lead Organizer 2019–Present Univ.