L. Papantonopoulos (Ed.) The Invisible Universe: Dark Matter and Dark Energy ABC Editor LefterisPapantonopoulos NationalTechnicalUniversityofAthens DepartmentofPhysics ZografouCampus 15780Athens,Greece [email protected] L.Papantonopoulos,TheInvisibleUniverse:DarkMatterandDarkEnergy,Lect.Notes Phys.720(Springer,BerlinHeidelberg2007),DOI10.1007/978-3-540-71013-4 LibraryofCongressControlNumber:2007923172 ISSN0075-8450 ISBN978-3-540-71012-7 SpringerBerlinHeidelbergNewYork Thisworkissubjecttocopyright. Allrightsarereserved,whetherthewholeorpartofthematerialis concerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation,broadcasting, reproductiononmicrofilmorinanyotherway,andstorageindatabanks.Duplicationofthispublication orpartsthereofispermitted onlyundertheprovisions oftheGermanCopyright LawofSeptember 9, 1965,initscurrentversion,andpermissionforusemustalwaysbeobtainedfromSpringer.Violations areliableforprosecutionundertheGermanCopyrightLaw. SpringerisapartofSpringerScience+BusinessMedia springer.com (cid:2)c Springer-VerlagBerlinHeidelberg2007 Theuseofgeneraldescriptivenames,registerednames,trademarks,etc.inthispublicationdoesnotimply, evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevantprotectivelaws andregulationsandthereforefreeforgeneraluse. Typesetting:bytheauthorsandIntegrausingaSpringerLATEXmacropackage Coverdesign:eStudioCalamarS.L.,F.Steinen-Broo,Pau/Girona,Spain Printedonacid-freepaper SPIN:12023448 543210 Preface This book is an edited version of the review talks given in the Third Aegean SchoolontheInvisibleUniverse:DarkMatterandDarkEnergy,heldinKarfas onChios Island, Greece,from26thof September to 1stofOctober 2005.The aim of this book is not to present another proceedings volume, but rather an advancedmultiauthoredtextbookwhichmeetstheneedsofboththepostgrad- uate students and the young researchers, in the fields of Modern Cosmology and Astrophysics. The issue of dark matter and dark energy is one of the central interest in Astroparticle Physics, Astrophysics, Astronomy, and Modern Cosmology. Muchofobservationaldataindicatethatthereisamissingmatterandmissing energy in the Universe. Evidence of the existence of this unknown form of matter and energy can be obtained from different sources. In Astrophysics, thedynamicsofgalaxyformationandgalaxyclusterscangiveinformationon the amount of missing matter. In Astroparticle physics, particle candidates wereproposedfromstringtheoryandsupersymmetrytoidentifytheunknown matter. In Cosmology, the recent data from Cosmic Microwave Background (CMB) and Supernovae Observations strongly indicate that there is a large amount of an unknown form of energy in the energy balance of the Universe. The purpose of this book is to present these issues and discuss in detail the physics involved. The first part of the book presents the problem of missing matter of the Universe as seen by Astroparticle Physics and Astrophysics. G. Lazaride’s chapter reviews the main proposals of particle physics for the composition of the dark matter in the universe. The lightest neutralino is the most popular candidate constituent of dark matter. Axinos and gravitinos can also con- tribute to dark matter. A model is presented which possesses a wide range of parameters consistent with the data on dark matter abundance as well as other phenomenological constraints. In view that many particle theories will be tested in the next round experiments in large accelerators, such as the Large Hadron Collider (LHC), a more phenomenological approach to dark matter in elementary particle physics is adopted in the next chapter by A. Lahanas. The interest in these experiments is that may provide candidates for dark matter of supersymmetric origin. VI Preface Amoredifficulttaskisundertakeninthenextchapter:thedirectdetection of supersymmetric dark matter. J. Vergados after reviewing supersymmetric modelswiththeirparametersconstrainedfromtherecentdataatlowenergies and cosmological observations, is suggesting experiments of direct detection of dark matter mainly through a neutralino-nucleus interaction. The challenge of dark matter is addressed in the context of Astrophysics by J. Silk’s chapter. It describes the confrontation of structure formation with observation and it focuses on the detection of the most elusive com- ponent, non–baryonic dark matter. It explains how galaxy formation theory is driven by phenomenology and by numerical simulations of dark matter clustering under gravity. Once the complications of star formation are incor- porated, the theory becomes very complex. Semi-analytical perspectives of thetheoryarepresentedthatmayshedsomeinsightintothenatureofgalaxy formation. ThesecondpartofthebookdealswiththeenergybalanceoftheUniverse. InthefirstchapterbyP.Tozzi,thebasicproceduresarepresentedtoconstrain the cosmological parameters which they describe the energy content of the Universe.DatafromclustersofgalaxiesandtheirX-raypropertiesareusedas cosmologicaltoolstodeduceinformationontheseparameters.Thedifficulties inanalysinggalaxyredshiftsurveysdatalikethe2dFGalaxyRedshiftSurvey (2dFGRS) and the Sloan Digital Sky survey (SDSS) are explained in W. Percival’s chapter. A very interesting example is provided of joint analysis of thelatestCMBandlarge-scalestructuredata,leadingtoasetofcosmological parameter constraints. The chapterbyR.Crittendendiscussesthe evidencefordarkenergycom- ing from a wide variety of data. After reviewing the physics of the CMB, it discusses the different methods that are used in determining the dark en- ergy’s density, evolution, and clustering properties and the crucial role the microwave background plays in all of these methods. L. Perivolaropoulos’s chapter deals with another interesting manifestation of the presence of dark energy in the Universe: the late time acceleration. It presents of the recent observationaldata obtained from type Ia supernovasurveys that support the accelerating expansion of the universe. The methods for the analysis of the dataarereviewedandthetheoreticalimplicationsobtainedfromtheiranalysis are discussed. The last chapter of the second part of the book by M. Sami is a pre- sentation of current theoretical models for dark energy. These models rely on scalar field dynamics and this chapter focusses mainly on the underlying basic features rather than on concrete scalar field models. The cosmological dynamics of standardscalarfields,phantoms, andtachyonfields is developed indetail.Scalingsolutionsarediscussedemphasizingtheirimportanceinmod- ellingdarkenergy.Thedevelopedconceptsareimplemented inanexampleof quintessential inflation. The third part of the book discusses the issue of dark matter and dark energybeyondthe standardtheoryof GeneralRelativity.Higher dimensional Preface VII string and brane theories are employed and also theories that modify the usual Newtonian dynamics. An introduction to high dimensional theories is given in I. Antoniadis’ chapter. The basic idea is that the apparent weakness of gravity can be accounted by the existence of large internal dimensions, in the submillimeter region, and transverse to a braneworld where our universe must be confined. The main properties of this scenario are reviewed and its implications for observationsat both particle colliders and in non-accelerator gravity experiments are discussed. These ideas are applied to Cosmology in R. Maartens’ chapter. As ex- plainedinL.Perivolaropoulos’contributionanacceleratingUniverserequires thepresenceofadarkenergyfieldwitheffectivelynegativepressure.Analter- nativetodarkenergyisthatgravityitselfmaybehavedifferentlyfromgeneral relativity on the largest scales, in such a way as to produce acceleration. In this chapteranexampleofmodified gravityis presentedwhichis providedby braneworld models that self-accelerate at late times. The challenges of dark matter and dark energy in the context of string theory are discussed in N. Mavromatos’s article. In this chapter the resolution of these issues in string theoryisbrieflyreviewedandasuggestionfortheresolutionofthedarkenergy issue is discussed. The most successful alternative to dark matter in bound gravitational systems is the modified Newtonian dynamics, or MOND, which is discussed in R. Sanders’ chapter. There, the various attempts to formulate MOND as a modification of General Relativity are presented and the covarianttheories that have been proposed as a basis for this idea are explained. Finally, local modifications of general relativity by making the Lagrangian an arbitrary function of the Ricci scalar are presented in R. Woodard’s contribution. The interestofsuchtheoriesisthattheycanreproducethecurrentphaseofcosmic acceleration without dark energy. The Third Aegean School and consequently this book became possible with the kind support of many people and organizations.The School was or- ganized by the Physics Department of the National Technical University of Athens, and supported by the Physics Department of King’s College, Uni- versity of London, the Institute of Cosmology and Gravitation, University of Portsmouth, the Physics and Astronomy Department, University of Ten- nessee.We also receivedfinancialsupportfrom the following sourcesandthis is gratefully acknowledged:Ministry ofNationalEducationand Religious Af- fairs, Prefecture of Chios, Municipality of Chios. WethankGiannisGialasforhisvaluableassistanceandhelpinorganizing the School in Chios and the University of the Aegean for providing technical support. We thank also the other members of the Organizing Committee of theSchool,AlexKehagias,GeorgeKoutsoumbas,GeorgeSiopsis,andNikolas Tracas for their help in organizing the School. The administrative support of the Third Aegean School was again taken up with great care by Mrs. Evelyn Pappa. We acknowledge the help of Vasilis Zamarias, who designed VIII Preface andmaintainedthewebsideoftheSchoolandassistedusinresolvingtechnical issues in the process of editing this book. Last,but notleast,we aregratefulto the staffofSpringer-Verlag,respon- sible for the Lecture Notes in Physics, whose abilities and help contributed greatly to the appearance of this book. Athens, October 2006 Lefteris Papantonopoulos Contents Part I Dark Matter: The Missing Matter of the Universe as Seen by Astroparticle Physics and Astrophysics 1 Particle Physics Approach to Dark Matter George Lazarides................................................. 3 1.1 Introduction ................................................ 3 1.2 Axions ..................................................... 4 1.3 Salient Features of MSSM .................................... 6 1.4 Neutralino Relic Abundance .................................. 9 1.5 Axinos ..................................................... 14 1.6 Gravitinos.................................................. 17 1.7 Yukawa Quasi-Unification .................................... 18 1.8 Conclusions................................................. 28 References ...................................................... 29 2 LSP as a Candidate for Dark Matter Athanasios Lahanas .............................................. 35 2.1 Introduction ................................................ 35 2.2 The Energy – Matter Content of the Universe................... 37 2.3 The Thermal Universe ....................................... 42 2.4 Dark Matter ................................................ 46 2.5 Calculating DM Relic Abundances............................. 48 2.6 Supersymmetry and its CosmologicalImplications ............... 54 2.7 Conclusions................................................. 65 References ...................................................... 66 3 On the Direct Detection of Dark Matter John Vergados................................................... 69 3.1 Introduction ................................................ 69 3.2 The Nature of the LSP....................................... 72 3.3 The Feynman Diagrams Entering the Direct Detection of LSP .... 72 X Contents 3.4 Going from the Quark to the Nucleon Level..................... 80 3.5 The Nucleon Cross Sections................................... 84 3.6 The Allowed SUSY Parameter Space........................... 84 3.7 Rates ...................................................... 85 3.8 Expressions for the Rates..................................... 87 3.9 Bounds on the Scalar Proton Cross Section ..................... 89 3.10 Exclusion Plots in the a ,a and σ ,σ Planes.................. 90 p n p n 3.11 The Modulation Effect ....................................... 92 3.12 Transitions to Excited States ................................. 93 3.13 The Directional Rates........................................ 93 3.14 Observation of Electrons Produced During the LSP-nucleus Collisions.................................... 96 3.15 Conclusions................................................. 97 References ...................................................... 98 4 Galaxy Formation and Dark Matter Joseph Silk......................................................101 4.1 Introduction ................................................101 4.2 Precision Cosmology.........................................102 4.3 The Global Baryon Inventory .................................104 4.4 The “Missing” Baryons ......................................105 4.5 Large-scaleStructure and Cold Dark Matter: The Issues..........106 4.6 Resurrection via Astrophysics .................................107 4.7 What Determines the Mass of a Galaxy? .......................109 4.8 Disk Galaxy Formation ......................................109 4.9 Spheroidal Galaxy Formation .................................111 4.10 Numerical Simulations .......................................112 4.11 The Case for Positive Feedback ...............................115 4.12 Observing Cold Dark Matter: Where Next?.....................117 4.13 Summary...................................................118 References ......................................................119 Part II Dark Energy: The Energy Balance of the Universe within the Standard Cosmological Model 5 Cosmological Parameters from Galaxy Clusters: An Introduction Paolo Tozzi .....................................................125 5.1 Introduction ................................................125 5.2 Clusters of Galaxies in a CosmologicalContext..................126 5.3 From Observations to CosmologicalParameters .................137 5.4 New Physics and Future Prospects.............................149 5.5 What to Bring Home ........................................154 References ......................................................155 Contents XI 6 Cosmological Constraints from Galaxy Clustering Will Percival ....................................................157 6.1 Introduction ................................................157 6.2 Basics......................................................158 6.3 Matter Perturbations ........................................159 6.4 The Evolution of Perturbations ...............................162 6.5 Galaxy Survey Analysis ......................................165 6.6 Practicalities................................................171 6.7 Results from Recent Surveys..................................174 6.8 Combination with CMB Data.................................175 References ......................................................184 7 Dark Energy and the Microwave Background Robert Crittenden................................................187 7.1 Introduction ................................................187 7.2 Models for Dark Energy......................................189 7.3 The Physics of the Microwave Background......................192 7.4 Ways of Probing Dark Energy.................................204 7.5 The Integrated Sachs-Wolfe Effect .............................209 7.6 Conclusions and Future Prospects .............................212 References ......................................................214 8 Models of Dark Energy M. Sami ........................................................219 8.1 Glimpses of FRW Cosmology .................................220 8.2 CosmologicalConstant Λ.....................................236 8.3 Dynamically Evolving Scalar Field Models of Dark Energy........239 8.4 Scaling Solutions in Models of Coupled Quintessence.............248 8.5 Quintessential Inflation.......................................249 8.6 Conclusions.................................................254 References ......................................................255 9 Accelerating Universe: Observational Status and Theoretical Implications Leandros Perivolaropoulos.........................................257 9.1 Introduction ................................................257 9.2 Expansion History from the Luminosity Distances of SnIa ........258 9.3 ObservationalResults ........................................265 9.4 Dark Energy and Negative Pressure............................269 9.5 Dynamical Evolution of Dark Energy ..........................278 9.6 The Fate of a Phantom Dominated Universe: Big Rip ............282 9.7 Future Prospects-Conclusion..................................284 References ......................................................287 XII Contents Part III Dark Matter and Dark Energy Beyond the Standard Theory of General Relativity 10 The Physics of Extra Dimensions Ignatios Antoniadis ..............................................293 10.1 Introduction ................................................293 10.2 Framework .................................................295 10.3 Experimental Implications in Accelerators ......................297 10.4 Supersymmetry in the Bulk and Short Range Forces .............302 10.5 ElectroweakSymmetry Breaking ..............................306 10.6 Standard Model on D-branes..................................309 10.7 Non-compact Extra Dimensions and Localized Gravity ...........312 References ......................................................319 11 Dark Energy from Brane-world Gravity Roy Maartens ...................................................323 11.1 Introduction ................................................323 11.2 KK Modes of the Graviton ...................................326 11.3 DGP Type Brane-worlds:Self-accelerating Cosmologies ..........327 11.4 Conclusion .................................................331 References ......................................................331 12 The Issue of Dark Energy in String Theory Nick Mavromatos ................................................333 12.1 Introduction ................................................333 12.2 De Sitter (dS) Universes from a Modern Perspective .............336 12.3 No Horizons in Perturbative (Critical) String Theory ............343 12.4 Dilaton Quintessence in String Theory .........................346 12.5 Conclusions.................................................369 References ......................................................372 13 Modified Gravity Without Dark Matter Robert Sanders ..................................................375 13.1 Introduction ................................................375 13.2 The Phenomenology of MOND................................377 13.3 Relativistic MOND ..........................................385 13.4 TeVeS: Successes, Issues and Modifications .....................393 13.5 Conclusions.................................................398 References ......................................................400 14 Avoiding Dark Energy with 1/R Modifications of Gravity Richard Woodard ................................................403 14.1 Introduction ................................................403 14.2 The Theorem of Ostrogradski.................................407 14.3 Common Misconceptions .....................................410