The five lectures presented in this volume address very timely mathematical problems in relativity and cosmology. "Part I" is devoted to the initial value and evolution problems of the Einstein equations. Especially it deals with the Einstein-Yang-Mills-Boltzmann system, fluid models with finite or infinite conductivity, global evolution of a new (two-phase) model for gravitational collapse and the structure of maximal, asymptotically flat, vacuum solutions of the constraint equations which have the additional property of containing trapped surfaces. "Part II" focuses on geometrical-topological problems in relativity and cosmology: on the role of cosmic censorship for the global structure of the Einstein-Maxwell equations and on the mathematical structure of quantum conformal superspace.

Manolis Plionis & Spiros Cotsakis plionis@sapfo. astro. noa. gr skot@aegean. gr Since the dawn of human civilisation natural phenomena have been subject to observation and investigation by the humans who initially ascribed to them 'divine' powers. Gods of 'good' and 'evil' werecreatedaccording to the useful- ness or notofsuch unexplained, atthetime, phenomena. Astheir understanding of the world developed and deepened, the divine powers, religious beliefs, su- perstitions and mysticism gave their place to the knowledge, limited that it may be, of physical reality. However, many issues have been and still are out of grasp of human understanding. These issues have always been at the center of philosophical, theological, and more recently, scientific debate. It is to us incredible that many of the conclusions concerning the true scientific explanation of the external world, to which the ancient Greeks arrived purely on the basis of abstract thought, came so near to modem scientific ideas and also form the basis of modem science. We cannot but stand with amazement at the original thoughts of Archimedes who, among his many extraordinary achieve- ments in mathematics and physics, calculated (cf. TheSandReckoner) the mass density of the observable universe and came up with a figure that is in complete agreement with current estimates coming from observational cosmology.

This book is written in a pedagogical style intelligible for graduate students. It reviews recent progress in black-hole and wormhole theory and in mathematical cosmology within the framework of Einstein's field equations and beyond, including quantum effects. This collection of essays, written by leading scientists of long standing reputation, should become an indispensable source for future research.

Thisbookisaneditedversionofthelecturesdeliveredduringthe1stAegean SummerSchoolonCosmology,heldonSamosisland,Greece,inSeptember 21-29,2001,andorganizedjointlybytheDepartmentofMathematics,U- versity of the Aegean and the Department of Physics, National Technical UniversityofAthens. Cosmology,thescienceoftheuniverse,standsatthecrossroadsofmany ?eldsofphysicsandmathematicsandpresentsuswithchallengingproblems of many forms. Although there are by now many textbooks discussing the subjectatmanylevels,itistruethatnosinglebookhasthecharacteristics wehadinmindwheneditingthisvolume. Wehavetriednottoproducea proceedingsvolumebutmoreamultiauthoredtextbookwhichcouldserveas areferencesourceofcurrentideasincosmology. Webelievethisbookcovers atanintroductorylevelmostoftheissueswhichareconsideredimportant inmoderncosmologicalresearchandcanbereadbyagraduatestudentor researcherwhowishestoacquireareasonableknowledgeofcosmologythat will,wehope,continuetobeofvalueforyearstocome. The 1st Aegean School on Cosmology, and consequently this book, - camepossiblewiththekindsupportofmanypeopleandorganizations. We received ?nancial support from the following sources and this is gratefully acknowledged: the Municipality of Karlovassi, the North Aegean Regional Secretariat, the Prefecture of Samos, the Ministry of the Aegean, and the NationalBankofGreece. TheadministrativesupportoftheSchoolwastakenupwithgreatcare byMrs. EvelynPappaandMantoKatsianiandwewouldliketothankthem bothfortheirkinde?ortstoresolvemanyissueswhicharosebefore,during andaftertheSchool. WeacknowledgethehelpofMr. NectariosBenekoswho designedandmaintainedthewebsiteoftheSchool. Last,butnotleast,wearegratefultothesta?ofSpringer-Verlag,resp- siblefortheLectureNotesinPhysics,whoseabilitiesandhelpcontributed greatlytothe?neappearanceofthisbook. Karlovassi,Samos, SpirosCotsakis March2002 EleftheriosPapantonopoulos TableofContents PartI HistoryandOverview 1 IsNatureGeneric? SpirosCotsakis,PeterG. L. Leach...3 1. 1 Introduction...3 1. 2 PrinciplesofCosmologicalModelling...4 1. 2. 1 Spacetimes...4 1. 2. 2 TheoriesofGravity...5 1. 2. 3 MatterFields...6 1. 3 Cosmologies...6 1. 4 CosmologicalProblems...8 1. 4. 1 TheSingularityProblem...8 1. 4. 2 TheProblemofCosmicTopology...9 1. 4. 3 TheProblemofAsymptoticStates...9 1. 4. 4 GravityTheoriesandtheEarlyUniverse...11 1. 5Outlook ...12 References...14 2 EvolutionofIdeasinModernCosmology AndreasParaskevopoulos...16 2. 1 Introduction...16 2. 2 TheBeginningsofModernCosmology(1917-1950)...17 2. 3 Cosmology1950-1970:HotBigBang, SingularitiesandQuantumApproach...20 2. 4 Cosmology1970-Thisbookisaneditedversionofthelecturesdeliveredduringthe1stAegean SummerSchoolonCosmology,heldonSamosisland,Greece,inSeptember 21-29,2001,andorganizedjointlybytheDepartmentofMathematics,U- versity of the Aegean and the Department of Physics, National Technical UniversityofAthens. Cosmology,thescienceoftheuniverse,standsatthecrossroadsofmany ?eldsofphysicsandmathematicsandpresentsuswithchallengingproblems of many forms. Although there are by now many textbooks discussing the subjectatmanylevels,itistruethatnosinglebookhasthecharacteristics wehadinmindwheneditingthisvolume. Wehavetriednottoproducea proceedingsvolumebutmoreamultiauthoredtextbookwhichcouldserveas areferencesourceofcurrentideasincosmology. Webelievethisbookcovers atanintroductorylevelmostoftheissueswhichareconsideredimportant inmoderncosmologicalresearchandcanbereadbyagraduatestudentor researcherwhowishestoacquireareasonableknowledgeofcosmologythat will,wehope,continuetobeofvalueforyearstocome. The 1st Aegean School on Cosmology, and consequently this book, - camepossiblewiththekindsupportofmanypeopleandorganizations. We received ?nancial support from the following sources and this is gratefully acknowledged: the Municipality of Karlovassi, the North Aegean Regional Secretariat, the Prefecture of Samos, the Ministry of the Aegean, and the NationalBankofGreece. TheadministrativesupportoftheSchoolwastakenupwithgreatcare byMrs. EvelynPappaandMantoKatsianiandwewouldliketothankthem bothfortheirkinde?ortstoresolvemanyissueswhicharosebefore,during andaftertheSchool. WeacknowledgethehelpofMr. NectariosBenekoswho designedandmaintainedthewebsiteoftheSchool. Last,butnotleast,wearegratefultothesta?ofSpringer-Verlag,resp- siblefortheLectureNotesinPhysics,whoseabilitiesandhelpcontributed greatlytothe?neappearanceofthisbook. Karlovassi,Samos, SpirosCotsakis March2002 EleftheriosPapantonopoulos TableofContents PartI HistoryandOverview 1 IsNatureGeneric? SpirosCotsakis,PeterG. L. Leach...3 1. 1 Introduction...3 1. 2 PrinciplesofCosmologicalModelling...4 1. 2. 1 Spacetimes...4 1. 2. 2 TheoriesofGravity...5 1. 2. 3 MatterFields...6 1. 3 Cosmologies...6 1. 4 CosmologicalProblems...8 1. 4. 1 TheSingularityProblem...8 1. 4. 2 TheProblemofCosmicTopology...9 1. 4. 3 TheProblemofAsymptoticStates...9 1. 4. 4 GravityTheoriesandtheEarlyUniverse...11 1. 5Outlook ...12 References...14 2 EvolutionofIdeasinModernCosmology AndreasParaskevopoulos...16 2. 1 Introduction...16 2. 2 TheBeginningsofModernCosmology(1917-1950)...17 2. 3 Cosmology1950-1970:HotBigBang, SingularitiesandQuantumApproach...20 2. 4 Cosmology1970-1990:Chaotic,In?ationary, QuantumandAlternative...22 2. 5ConclusionsandOutlook ...25 References...26 VIII TableofContents PartII MathematicalCosmology 3ConstraintsandEvolutioninCosmology YvonneChoquet-Bruhat,JamesW. York...29 3. 1 Introduction...29 3. 2 MovingFrameFormulas...30 3. 2. 1 FrameandCoframe...30 3. 2. 2 Metric...31 3. 2. 3 Connection...31 3. 2. 4 Curvature ...32 3. 3 (n+1)-SplittingAdaptedtoSpaceSlices ...33 3. 3. 1 De?nitions...33 3. 3. 2 StructureCoe?cients...34 3. 3. 3 SplittingoftheConnection ...

This book has grown out of lectures held at a summer school on cosmology, in response to an ever increasing need for an advanced textbook that addresses the needs of both postgraduate students and nonspecialist researchers from various disciplines ranging from mathematical physics to observational astrophysics. Bridging the gap between standard textbook material in cosmology and the forefront of research, this book also constitutes a modern source of reference for the experienced researcher in classical and quantum cosmology.

Manolis Plionis & Spiros Cotsakis plionis@sapfo. astro. noa. gr skot@aegean. gr Since the dawn of human civilisation natural phenomena have been subject to observation and investigation by the humans who initially ascribed to them 'divine' powers. Gods of 'good' and 'evil' werecreatedaccording to the useful- ness or notofsuch unexplained, atthetime, phenomena. Astheir understanding of the world developed and deepened, the divine powers, religious beliefs, su- perstitions and mysticism gave their place to the knowledge, limited that it may be, of physical reality. However, many issues have been and still are out of grasp of human understanding. These issues have always been at the center of philosophical, theological, and more recently, scientific debate. It is to us incredible that many of the conclusions concerning the true scientific explanation of the external world, to which the ancient Greeks arrived purely on the basis of abstract thought, came so near to modem scientific ideas and also form the basis of modem science. We cannot but stand with amazement at the original thoughts of Archimedes who, among his many extraordinary achieve- ments in mathematics and physics, calculated (cf. TheSandReckoner) the mass density of the observable universe and came up with a figure that is in complete agreement with current estimates coming from observational cosmology.

This book is written in a pedagogical style intelligible for graduate students. It reviews recent progress in black-hole and wormhole theory and in mathematical cosmology within the framework of Einstein's field equations and beyond, including quantum effects. This collection of essays, written by leading scientists of long standing reputation, should become an indispensable source for future research.