DOCSLIB.ORG

Astro2020 Science White Paper Dark Energy and Modified Gravity

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Astro2020 Science White Paper Dark Energy and Modified Gravity Astro2020 Science White Paper Dark Energy and Modified Gravity Thematic Areas: Cosmology and Fundamental Physics Principal Author: Name: Anˇze Slosar Institution: Brookhaven National Laboratory Email: [email protected] Phone: (631) 344 8012 Co-authors: See next page. Endorsing Collaborations: The surveys designed to carry out dark energy and cosmology investigations in the next decade have attracted large collaborations, organized to facilitate many diverse science goals and broad participation within unified data sets. The following collaborations involving over a thousand people are co-signing this white paper to endorse its content, having reviewed it following their respective internal management processes: • The Dark Energy Spectroscopic Instrument Collaboration (DESI), • The Euclid Consortium, • The LSST Dark Energy Science Collaboration (LSST-DESC), • The Simons Observatory Collaboration (SO), • The WFIRST Cosmology Science Investigation Teams Abstract: Despite two decades of tremendous experimental and theoretical progress, the riddle of the accelerated expansion of the Universe remains to be solved. On the experimental side, our understanding of the possibilities and limitations of the major dark energy probes has evolved; here we summarize the major probes and their crucial challenges. On the theoretical side, the taxonomy of explanations for the accelerated expansion rate is better understood, providing clear guidance to the relevant observables. We argue that: i) improving statistical precision and systematic control by taking more data, supporting research efforts to address crucial challenges arXiv:1903.12016v1 [astro-ph.CO] 28 Mar 2019 for each probe, using complementary methods, and relying on cross-correlations is well motivated; ii) blinding of analyses is difficult but ever more important; iii) studies of dark energy and modified gravity are related; and iv) it is crucial that R&D for a vibrant dark energy program in the 2030s be started now by supporting studies and technical R&D that will allow embryonic proposals to mature. Understanding dark energy, arguably the biggest unsolved mystery in both fundamental particle physics and cosmology, will remain one of the focal points of cosmology in the forthcoming decade. Co-authors / Endorsers: Kevork N. Abazajian1, Zeeshan Ahmed2, David Alonso3, Mustafa A. Amin4, Behzad Ansarinejad5, Robert Armstrong6, Jacobo Asorey7, Arturo Avelino8, Santiago Avila9, Carlo Baccigalupi10,11,12, Mario Ballardini13, Kevin Bandura14,15, Nicholas Battaglia16, Amy N. Bender17, Charles Bennett18, Bradford Benson19,20, Florian Beutler21, F. Bianchini22, Maciej Bilicki23, Colin Bischoff24, Andrea Biviano25, Jonathan Blazek26,27, Lindsey Bleem17,20, Adam S. Bolton28, J. Richard Bond29, Julian Borrill30, Sownak Bose8, Alexandre Boucaud31, Franc¸ois R. Bouchet32, Elizabeth Buckley-Geer19, Philip Bull33, Zheng Cai34, John E. Carlstrom35,20,17, Francisco J Castander36, Emanuele Castorina37, Anthony Challinor38,39,40, Tzu-Ching Chang41, Jon´as Chaves-Montero17, Nora Elisa Chisari3, Douglas Clowe42, Johan Comparat43, Asantha Cooray1, Rupert A. C. Croft44, Francis-Yan Cyr-Racine45,46, Guido D’Amico47, Tamara M Davis48, Kyle Dawson49, Marcel Demarteau17, Arjun Dey28, Olivier Dor´e41, Yutong Duan50, Joanna Dunkley51, Cora Dvorkin45, Alexander Eggemeier5, Daniel Eisenstein8, John Ellison52, Alexander van Engelen29, Stephanie Escoffier53, Giulio Fabbian54, Simone Ferraro30, Pedro G. Ferreira3, Andreu Font-Ribera55, Simon Foreman29, Pablo Fosalba36, Oliver Friedrich40, Juan Garc´ıa-Bellido9,56, Martina Gerbino17, Mandeep S.S. Gill57,47,2, Vera Gluscevic58, Satya Gontcho A Gontcho59, Krzysztof M. G/’orski41, Daniel Gruen57,47, Jon E. Gudmundsson60, Nikhel Gupta22, Julien Guy30, Shaul Hanany61, Will Handley40,62, C´esar Hern´andez-Aguayo63, J. Colin Hill64,65, Christopher M. Hirata27, Ren´ee Hloˇzek66,67, Gilbert Holder68, Dragan Huterer69, Mustapha Ishak70, Tesla Jeltema34,71, Saurabh W. Jha72, Johann Cohen-Tanugi73, Bradley Johnson74, Marc Kamionkowski18, Kirit S. Karkare35,20, Ryan E. Keeley7, Rishi Khatri75, David Kirkby1, Theodore Kisner30, Jean-Paul Kneib26, Lloyd Knox76, Savvas M. Koushiappas77, Ely D. Kovetz78, Kazuya Koyama21, Elisabeth Krause79, Benjamin L’Huillier7, Ofer Lahav55, Massimiliano Lattanzi80, Danielle Leonard44, Michael Levi30, Michele Liguori81, Anja von der Linden82, Marilena Loverde82, Zarija Luki´c30, Axel de la Macorra83, Mathew Madhavacheril51, Andr´es Plazas51, Alessio Spurio Mancini40, Marc Manera84, Adam Mantz47, Paul Martini27, Kiyoshi Masui85, Jeff McMahon69, P. Daniel Meerburg40,39,86, James Mertens87,88,29, Joel Meyers89, Surhud More90, Pavel Motloch29, Suvodip Mukherjee32, Julian B. Mu˜noz45, Adam D. Myers91, Johanna Nagy66, Nathalie Palanque-Delabrouille92, Laura Newburgh93, Jeffrey A. Newman94, Michael D. Niemack16, Gustavo Niz95, Andrei Nomerotski96, Paul O’Connor96, Lyman Page51, Antonella Palmese19, Mariana Penna-Lima97, Will J. Percival98,99,88, Francesco Piacentni100,101, Matthew M. Pieri53, Elena Pierpaoli102, Levon Pogosian103, Abhishek Prakash104, Clement Pryke61, Giuseppe Puglisi47,57, Radek Stompor31, Marco Raveri20,35, Christian L. Reichardt22, Jason Rhodes41, Steven Rodney105, Benjamin Rose106, Ashley J. Ross27, Graziano Rossi107, John Ruhl108, Benjamin Saliwanchik93, Lado Samushia109, Javier S´anchez1, Misao Sasaki110, Emmanuel Schaan30,37, David J. Schlegel30, Marcel Schmittfull64, Michael Schubnell69, Douglas Scott111, Neelima Sehgal82, Leonardo Senatore57, Hee-Jong Seo42, Arman Shafieloo7, Huanyuan Shan112, Blake D. Sherwin39,40, Feng Shi7, Sara Simon69, Anˇze Slosar96, Suzanne Staggs51, Glenn Starkman108, Albert Stebbins19, Aritoki Suzuki30, Eric R. Switzer113, Peter Timbie114, Andrew J. Tolley115, Matthieu Tristram116, Mark Trodden117, M. A. Troxel118, M. A. Troxel119, Cora Uhlemann39, Caterina Umilt`a24, L. Arturo Uren˜na-L´opez95, Eleonora Di Valentino120, M. Vargas-Maga˜na83, Abigail Vieregg35, Christopher W. Walter119, Yi Wang121, Scott Watson122, Martin White123,30, Nathan Whitehorn124, W. L. K. Wu20, Weishuang Xu45, Siavash Yasini102, Matias Zaldarriaga64, Gong-Bo Zhao125,21, Yi Zheng126, Hong-Ming Zhu37,30, Ningfeng Zhu117, Joe Zuntz127, 1 University of California, Irvine, CA 92697 22 School of Physics, The University of 2 SLAC National Accelerator Laboratory, Melbourne, Parkville, VIC 3010, Australia Menlo Park, CA 94025 23 Center for Theoretical Physics, Polish 3 The University of Oxford, Oxford OX1 3RH, Academy of Sciences, al. Lotnik´ow 32/46, UK 02-668, Warsaw, Poland 4 Department of Physics & Astronomy, Rice 24 University of Cincinnati, Cincinnati, OH University, Houston, Texas 77005, USA 45221 5 Department of Physics, Lower Mountjoy, 25 INAF - Osservatorio Astronomico di South Rd, Durham DH1 3LE, United Kingdom Trieste, Via G.B. Tiepolo 11, 34143 Trieste, 6 Lawrence Livermore National Laboratory, Italy Livermore, CA, 94550 26 Institute of Physics, Laboratory of 7 Korea Astronomy and Space Science Astrophysics, Ecole Polytechnique F´ed´erale de Institute, Daejeon 34055, Korea Lausanne (EPFL), Observatoire de Sauverny, 8 Harvard-Smithsonian Center for 1290 Versoix, Switzerland Astrophysics, MA 02138 27 The Ohio State University, Columbus, OH 9 Universidad Aut´onoma de Madrid, 28049, 43212 Madrid, Spain 28 National Optical Astronomy Observatory, 10 SISSA - International School for Advanced 950 N. Cherry Ave., Tucson, AZ 85719 USA Studies, Via Bonomea 265, 34136 Trieste, 29 Canadian Institute for Theoretical Italy Astrophysics, University of Toronto, Toronto, 11 IFPU - Institute for Fundamental Physics of ON M5S 3H8, Canada the Universe, Via Beirut 2, 34014 Trieste, Italy 30 Lawrence Berkeley National Laboratory, 12 INFN – National Institute for Nuclear Berkeley, CA 94720 Physics, Via Valerio 2, I-34127 Trieste, Italy 31 Laboratoire Astroparticule et Cosmologie 13 Department of Physics & Astronomy, (APC), CNRS/IN2P3, Universit´eParis University of the Western Cape, Cape Town Diderot, 10, rue Alice Domon et L´eonie 7535, South Africa Duquet, 75205 Paris Cedex 13, France 14 CSEE, West Virginia University, 32 Institut d’Astrophysique de Paris (IAP), Morgantown, WV 26505, USA CNRS & Sorbonne University, Paris, France 15 Center for Gravitational Waves and 33 Queen Mary University of London, Mile Cosmology, West Virginia University, End Road, London E1 4NS, United Kingdom Morgantown, WV 26505, USA 34 University of California at Santa Cruz, 16 Cornell University, Ithaca, NY 14853 Santa Cruz, CA 95064 17 HEP Division, Argonne National 35 University of Chicago, Chicago, IL 60637 Laboratory, Lemont, IL 60439, USA 36 Institute of Space Sciences (ICE, CSIC), 18 Johns Hopkins University, Baltimore, MD Campus UAB, Carrer de Can Magrans, s/n, 21218 08193 Barcelona, Spain 19 Fermi National Accelerator Laboratory, 37 Department of Physics, University of Batavia, IL 60510 California Berkeley, Berkeley, CA 94720, 20 Kavli Institute for Cosmological Physics, USA Chicago, IL 60637 38 Institute of Astronomy, University of 21 Institute of Cosmology & Gravitation, Cambridge,Cambridge CB3 0HA, UK University of Portsmouth, Dennis Sciama 39 DAMTP, Centre for Mathematical Sciences, Building, Burnaby Road, Portsmouth PO1 Wilberforce Road, Cambridge, UK, CB3 0WA 3FX, UK 40 Kavli Institute for Cosmology, Cambridge, UK, CB3 0HA 61 University of Minnesota, Minneapolis, MN 41 Jet Propulsion Laboratory, California 55455 Institute of Technology, Pasadena, CA, USA 62 Astrophysics Group, Cavendish Laboratory, 42 Department of Physics and Astronomy, J.J.Thomson Avenue, Cambridge,
Load more

Recommended publications
  • Color1claudia De Rham – Professor [-20Pt] Imperial College London Physics Department, Theoretical Physics Group
    Claudia de Rham Imperial College London Professor Physics Department, Theoretical Physics Group Research Interests My expertise lies at the interface between Gravity, Cosmology and Particle Physics where I develop and test new models and paradigms. I apply field theory techniques to gravity and cosmology to tackle some of the outstanding open questions in physics from the nature of gravity, its embedding in a consistent high energy completion, the origin and evolution of our Universe and the late-time acceleration of the Universe. Current Appointments Since 2018 Imperial College London, Theoretical Physics group, London, UK, Professor. Since 2018 Perimeter Institute for Theoretical Physics, ON, Canada, Simons Emmy Noether Visiting Fellow. Since 2019 Case Western Reserve University, OH, USA, Adjunct Professor of Physics. Past Academic Positions 2016 – 2018 Imperial College London, Theoretical Physics group, London, UK, Reader. 2017 – 2019 Case Western Reserve University, OH, USA, Adjunct Associate Professor of Physics. 2011 – 2016 Case Western Reserve University, Department of Physics, Cleveland, OH, USA, Assistant Professor, (tenure–track) then Associate Professor, (tenured). 2010 – 2011 Geneva University, Department of Theoretical Physics, Geneva, Switzerland, SNSF Assistant Professor. 2006 – 2009 McMaster University, Hamilton, Canada. & Perimeter Institute for Theoretical Physics, Waterloo, Canada. Joint postdoctoral position in Cosmology. 2005 – 2006 McGill University, Physics Department, Montreal, Canada. Postdoctoral position in Cosmology. Education and Training 2002 – 2005 PhD from DAMTP, Cambridge University, UK. PhD Advisor: Prof. Anne-Christine Davis. 1998 – 2000 MSc, Ecole Polytechnique of Paris, France. 1996 – 2001 MSc, physics at EPFL, Ecole Polytechnique of Lausanne, Switzerland. Grants & Fundings 2020 – 2025 Named as 2020 Simons Foundation Investigator. 2020 – 2023 Co-I on STFC Group Grant, PI: Prof.
    [Show full text]
  • Living on a Ds Brane: Effects of KK Modes on Inflation
    Syracuse University SURFACE Physics College of Arts and Sciences 2-6-2007 Living on a dS Brane: Effects of KK modes on Inflation Scott Watson Department of Physics, Syracuse University, Syracuse, NY Claudia De Rham Dept. of Physics & Astronomy, McMaster University, Hamilton ON Follow this and additional works at: https://surface.syr.edu/phy Part of the Physics Commons Recommended Citation Watson, Scott and Rham, Claudia De, "Living on a dS Brane: Effects of KK modes on Inflation" (2007). Physics. 411. https://surface.syr.edu/phy/411 This Article is brought to you for free and open access by the College of Arts and Sciences at SURFACE. It has been accepted for inclusion in Physics by an authorized administrator of SURFACE. For more information, please contact [email protected]. Living on a dS brane: Effects of KK modes on inflation Claudia de Rham1,2, ∗ and Scott Watson3, † 1Dept. of Physics & Astronomy, McMaster University, Hamilton ON, Canada 2Perimeter Institute for Theoretical Physics, Waterloo, ON, Canada 3Physics Department, University of Toronto, Toronto, ON, Canada (Dated: February 2, 2008) We develop a formalism to study non-local higher-dimensional effects in braneworld sce- narios from a four-dimensional effective theory point of view and check it against the well- known Garriga-Tanaka result in the appropriate limit. We then use this formalism to study the spectrum of density perturbations during inflation as seen from the lower-dimensional effective theory. In particular, we find that the gravitational potential is greatly enhanced at short wavelengths. The consequences to the curvature perturbations are nonetheless very weak and will lead to no characteristic signatures on the power spectrum.
    [Show full text]
  • Cascading Gravity: Extending the Dvali-Gabadadze-Porrati Model to Higher Dimension
    PHYSICAL REVIEW LETTERS week ending PRL 100, 251603 (2008) 27 JUNE 2008 Cascading Gravity: Extending the Dvali-Gabadadze-Porrati Model to Higher Dimension Claudia de Rham,1,2 Gia Dvali,3,4 Stefan Hofmann,1,5 Justin Khoury,1 Oriol Pujola`s,4 Michele Redi,4,6 and Andrew J. Tolley1 1Perimeter Institute for Theoretical Physics, 31 Caroline St. N., Waterloo, ON, N2L 2Y5, Canada 2Department of Physics & Astronomy, McMaster University, Hamilton ON, L8S 4M1, Canada 3CERN, Theory Division, CH-1211 Geneva 23, Switzerland 4Center for Cosmology and Particle Physics, New York University, New York, New York 10003, USA 5NORDITA, Roslagstullsbacken 23, 106 91 Stockholm, Sweden 6Institut de The´orie des Phe´nome`nes Physiques, EPFL, CH-1015, Lausanne, Switzerland (Received 15 January 2008; published 27 June 2008) We present a generalization of the Dvali-Gabadadze-Porrati scenario to higher codimensions which, unlike previous attempts, is free of ghost instabilities. The 4D propagator is made regular by embedding our visible 3-brane within a 4-brane, each with their own induced gravity terms, in a flat 6D bulk. The model is ghost-free if the tension on the 3-brane is larger than a certain critical value, while the induced metric remains flat. The gravitational force law ‘‘cascades’’ from a 6D behavior at the largest distances followed by a 5D and finally a 4D regime at the shortest scales. DOI: 10.1103/PhysRevLett.100.251603 PACS numbers: 11.25.Wx, 04.50.Kd, 98.80.Cq Z Introduction.—The present acceleration of the Universe 1 4ᮀ 3ᮀ 2ᮀ S M M zM y z is a profound mystery.
    [Show full text]
  • TURNING GRAVITY UPSIDE DOWN Dr Ana Mijic Says Now Is the Time for Professors Claudia De Rham and Andrew Copyright © 2019
    Im Imperial/47 THE MAGAZINE FOR THE IMPERIAL COMMUNITY WINTER 2019/20 £7.95 WHERE SOLD pe Returning to Imperial was the best decision “With Executive Education, rial I benefited once again from outstanding academics delivering invaluable, current content and methodologies for immediate, real-world applications.” Jon Lipton, Management Consultant, Executive MBA 2017 graduate and Complete Course in Risk Management /47 2019 attendee TURNING GRAVITY All Imperial alumni are eligible for a 20 per cent discount UPSIDE across our range of short courses spanning finance, management, innovation and health. DOWN Visit imprl.biz/Imperial-alum Contact us: Im +44 (0)20 8742 3355 marti nrandall.com ATOL 3622 | ABTA Y6050 | AITO 5085 pe From Dubrovnik to Bengal, CONTENTS rial cruises with cultural depth. The world looks diff erent from the water and our journeys by sea and river are full of fresh Sailing the Dalmati an Coast perspecti ves. As well as the pleasure of travelling through spectacular scenery in a privately 25 April–5 May 2020 chartered fi rst-class vessel, each voyage promises to excite the mind, whether it’s exploring 5–15 May 2020 /47 ancient towns on the Dalmati an Coast, hearing concerts in historic venues along Europe’s Music Along the Rhine great rivers or cruising through India’s layered past – all in the company of expert lecturers. 30 June–7 July 2020 ‘I loved every day, every lecture and every port that we visited. The Danube: The Dalmati an Coast was the most beauti ful adventure I could have ever imagined.’ Celebrati ng Beethoven
    [Show full text]
  • Bimetric Gravity Is Cosmologically Viable
    Physics Letters B 748 (2015) 37–44 Contents lists available at ScienceDirect Physics Letters B www.elsevier.com/locate/physletb Bimetric gravity is cosmologically viable Yashar Akrami a,b, S.F. Hassan a,c, Frank Könnig a,b, Angnis Schmidt-May a,d, ∗ Adam R. Solomon a,b,e, a Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden b Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany c Department of Physics and the Oskar Klein Centre, Stockholm University, AlbaNova University Center, SE 106 91 Stockholm, Sweden d Institut für Theoretische Physik, Eidgenössische Technische Hochschule Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich, Switzerland e DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Rd., Cambridge CB3 0WA, UK a r t i c l e i n f o a b s t r a c t Article history: Bimetric theory describes gravitational interactions in the presence of an extra spin-2 field. Previous Received 4 May 2015 work has suggested that its cosmological solutions are generically plagued by instabilities. We show that Received in revised form 25 June 2015 by taking the Planck mass for the second metric, M f , to be small, these instabilities can be pushed Accepted 25 June 2015 back to unobservably early times. In this limit, the theory approaches general relativity with an effective Available online 29 June 2015 cosmological constant which is, remarkably, determined by the spin-2 interaction scale. This provides Editor: M. Trodden a late-time expansion history which is extremely close to CDM, but with a technically-natural value Keywords: for the cosmological constant.
    [Show full text]
  • Gravitational Waves and Their Primordial Power Spectrum from Inflation
    IMPERIAL COLLEGE LONDON DEPARTMENT OF PHYSICS Gravitational Waves and their Primordial Power Spectrum from Inflation Author: Nikola Kolev (CID: 01055052) Date: September 28, 2020 Abstract With the construction of LIGO and VERGO, there has been a plethora of new research in to what gravitational waves may tell us about the universe. At the moment, the only information we have about the primordial gravitational waves comes from observing the CMB. Although unlikely to be seen by the first generation of observatories, it is important to make predictions of the primordial gravitational wave spectrum now before it has been measured. We look at the possible primordial gravitational waves produced by a non-specific theory of inflation. We start with a review of some of the theory for linearised General Relativity, first with a massless graviton and then also for the massive case. The linearised action is derived in each case for Minkowski and FRW spacetimes. We also delve a little into bimetric gravity’s prediction for the primordial spectrum in a low energy limit using the dRGT Lagrangian. 2 Acknowledgements My most important thanks has to go out to my parents who not only made this year possible, but my whole schooling up to this point. They have given me the chance to follow my desires at university and to do so without many of the stresses commonplace in students, whether that be from material or moral support. It was a strange experience to write a dissertation while not being able to talk face-to-face with my supervisor and with a blackboard at hand.
    [Show full text]
  • Department of Physics
    department of physics of department Display of a candidate event in which a Higgs boson decays into two muons. CMS Experiment at the LHC, CERN. department of physics Data recorded: 2018-Jul-18 22:42:55.530432 GMT. biennial report 2018–2019 Run/Event/LS: 319639/961085861/624. Image: CERN (CMS Collaboration & T. McCauley) • biennial report 2018 report biennial – 2019 técnico lisboa técnico lisboa department of physics biennial report 2018–2019 acronyms 5 introduction 6 message from the president 7 the presidents of the physics department 10 departmental activities 12 organization of the department of physics 14 the department in numbers 16 education 18 engineering physics 19 the meft curriculum 21 doctoral program in physics 27 doctoral program in engineering physics 29 doctoral theses in physics 31 doctoral theses in engineering physics 33 master theses 37 pedagogical honours and awards 44 scientific areas 48 astrophysics and gravitation 49 condensed matter and nanotechnology 52 interdisciplinary physics 57 particle and nuclear physics 59 plasmas, lasers and nuclear fusion 63 scientific activities 66 nobel and ist distinguished lectures 67 table of contents df colloquia 68 research seminars 70 conferences and workshops 81 schools 83 scientific publications 84 books 116 science and society 118 support to nfist activities 120 physics olympiads 121 ist day: keep in touch 121 ipho 2018/49th international physics olympiad 122 meft: challenging the limits of science and technology 123 meft: extending the limits of science and technology 123 newtonmas 124 visits from schools 125 outreach seminars at schools and other institutions 126 faculty and staff 128 ackowledgement to collaborators 129 list of faculty and staff 130 faculty 132 administrative staff 203 PART 1 INTRODUCTION CMS event displays of Higgs to two photon candidate.
    [Show full text]
  • Lecture 8 Handout
    74th Arthur H. Compton Lectures Fall 2011 Massive Gravity Lecture 8 - November 19th, 2011 Today we will talk about a subject that got its start in 1939, but which has had an explosion of progress in the past 18 months: massive gravity. Massive gravity is the name we have given to the attempt to understand what the gravitational force would be like if the graviton has a mass. General relativity, Einstein’s theory of gravity, is special because it is the unique theory of a massless graviton. General relativity is both elegant and highly complex, so it is not a simple thing to figure out if it can be modified to allow the graviton to have a mass! The idea of massive gravity has a crazy history: • Fierz-Pauli action: Wolfgang Pauli and Markus Fierz were the first to figure out how one might add a mass to a graviton. Their theory was only an approximate theory, but intriguingly the theory they found was unique, like GR. • vDVZ discontinuity: this is the name given to the discovery, by van Dam, Veltman, and Zakharov in 1970 that Fierz-Pauli approximate theory could never agree with observations in the Solar System because of a mismatch between the gravitational force and gravitational lensing. Pauli and Fierz, who first considered how to • Vainshtein mechanism: in 1972, Arkady Vainshtein add a mass to gravity in 1939 figured out a way around the vDVZ discontinuity by pointing out that theories that improve on the Fierz- Pauli approximation will avoid the discontinuity • Boulware-Deser ghost: Also in 1972, Boulware and Deser showed that unless something special happens, any theory that fixes the vDVZ discontinuity will possess a “ghost” instability, which is essentially evidence that the theory is internally inconsistent.
    [Show full text]
  • Testing Some Scenarios in Modified Gravity
    Title Testing some scenarios in modified gravity Author(s) Arraut, Ivan Citation Issue Date Text Version ETD URL https://doi.org/10.18910/34062 DOI 10.18910/34062 rights Note Osaka University Knowledge Archive : OUKA https://ir.library.osaka-u.ac.jp/ Osaka University Testing some scenarios in modified gravity Iv´anDar´ıoArraut Guerrero Thesis for the PhD course Student:Iv´anDar´ıoArraut Guerrero Osaka University Faculty of Science Department of Physics Osaka, Toyonaka city, Japan January 10TH; 2014 Testing some scenarios in modified gravity Iv´anDar´ıoArraut Guerrero, Osaka University January 10TH; 2014 Abstract Modified gravity theories have emerged as an alternative for solving the dark energy and dark matter problems by introducing additional degrees of freedom inside the standard grav- itational theory. These extra degrees of freedom might be problematic at the moment of analyzing some scenarios where they can reproduce some pathologies, generally absent in- side the standard formulation of gravity (General Relativity). In this document, we analyze two modifications of gravity. The first one corresponds to the de-Rham-Gabadadze-Tolley (dRGT) theory of non-linear massive gravity which is a candidate for solving the dark energy problem. In this theory we study the perturbative behavior of the Schwarzschild de-Sitter (S- dS) solution with one free parameter satisfying β = α2. We find that the linear perturbation equations become identical to those for the vacuum Einstein theory when they are expressed in terms of the gauge-invariant variables. This implies that this black hole is stable in the dRGT theory as far as the spacetime structure is concerned in contrast to the case of the bi-Schwarzschild solution in the bi-metric theory.
    [Show full text]
  • Bimetric Gravity Is Cosmologically Viable
    Research Collection Journal Article Bimetric gravity is cosmologically viable Author(s): Akramia, Yashar; Hassan, S.F.; Könnig, Frank; Schmidt-May, Angnis; Solomon, Adam R. Publication Date: 2015-09-02 Permanent Link: https://doi.org/10.3929/ethz-b-000107104 Originally published in: Physics Letters B 748, http://doi.org/10.1016/j.physletb.2015.06.062 Rights / License: Creative Commons Attribution 4.0 International This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library Physics Letters B 748 (2015) 37–44 Contents lists available at ScienceDirect Physics Letters B www.elsevier.com/locate/physletb Bimetric gravity is cosmologically viable Yashar Akrami a,b, S.F. Hassan a,c, Frank Könnig a,b, Angnis Schmidt-May a,d, ∗ Adam R. Solomon a,b,e, a Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden b Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany c Department of Physics and the Oskar Klein Centre, Stockholm University, AlbaNova University Center, SE 106 91 Stockholm, Sweden d Institut für Theoretische Physik, Eidgenössische Technische Hochschule Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich, Switzerland e DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Rd., Cambridge CB3 0WA, UK a r t i c l e i n f o a b s t r a c t Article history: Bimetric theory describes gravitational interactions in the presence of an extra spin-2 field. Previous Received 4 May 2015 work has suggested that its cosmological solutions are generically plagued by instabilities.
    [Show full text]
  • Arxiv:1812.03136V2 [Gr-Qc] 22 Jun 2019
    A Complementary Third Law for Black Hole Thermodynamics Yuan Yao,1 Meng-Shi Hou,1 and Yen Chin Ong1, 2, 3, l 1Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, 180 Siwangting Road, Yangzhou City, Jiangsu Province 225002, China 2School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai 200240, China 3Nordita, KTH Royal Institute of Technology & Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm, Sweden There are some examples in the literature, in which despite the fact that the underlying theory or model does not impose a lower bound on the size of black holes, the final temperature under Hawking evaporation is nevertheless finite and nonzero. We show that under some loose conditions, the black hole is necessarily an effective remnant, in the sense that its evaporation time is infinite. That is, the final state that there is nonzero finite temperature despite having no black hole remaining cannot be realized. We discuss the limitations, subtleties, and the implications of this result, which is reminiscent of the third law of black hole thermodynamics, but with the roles of temperature and size interchanged. We therefore refer to our result as the \complemetary third law" for black hole thermodynamics. I. INTRODUCTION: THE ISSUE WITH From here onwards, we set ~ = c = G = kB = 1, unless TEMPERATURE OF BLACK HOLE REMNANTS when explicitly restored for clarity. Note that if α ∼ O(1), as is usually considered in theoretical calculation, then In the usual picture of Hawking evaporation, an asymp- the correction term becomes important at Planck scale. totically flat Schwarzschild black hole evaporates com- It has been argued that this leads to a correction in the pletely in finite time, although the time scale is extremely Hawking temperature, resulting in a black hole remnant long for a stellar mass black hole1.
    [Show full text]
  • Stable FLRW Solutions in Generalized Massive Gravity
    Preprint submitted to Int. J. Mod. Phys. D c 2014,World Scientific Publishing Company Stable FLRW solutions in Generalized Massive Gravity Claudia de Rham,a Matteo Fasielloa;b and Andrew J. Tolleya aDepartment of Physics, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA bStanford Institute for Theoretical Physics, Department of Physics, Stanford University, Stanford, CA 94305, USA E-mails: [email protected], [email protected], [email protected] Abstract. We present exact FLRW solutions in generalized massive gravity where the mass parameters are naturally promoted to Lorentz-invariant functions of the St¨uckelberg fields. This new dependence relaxes the constraint that would otherwise prevent massive gravity from possessing exact FLRW solutions. It does so without the need to introduce additional degrees of freedom. We find self-accelerating cosmological solutions and show that, with a mild restriction on the region of phase space, these cosmological solutions exhibit full stability, i.e. absence of ghosts and gradient instabilities for all the tensor, vector and scalar modes, for all cosmic time. We perform the full decoupling limit analysis, including vector degrees of arXiv:1410.0960v1 [hep-th] 3 Oct 2014 freedom, which can be used to confirm the existence of an active Vainshtein mechanism about these solutions. Contents 1 Introduction1 2 Exact FLRW solutions in Generalized Massive Gravity4 2.1 From manifest Lorentz invariance to Cosmology5 2.2 Zero spatial curvature scaling limit and Decoupling
    [Show full text]