4Zwicky & the Missing Mass Measured galaxy speeds in ComaVirial theorem: M/L ~ 500 M_sun/L_sunThe “missing mass”An outstanding problem in cosmology90-98% of the universe is in a mysterious formdetectable only by its gravitational attraction
5The Dark Matter PuzzleWhere is it?How much is there?What is it?
6Cosmology in a nutshell: The old cosmologyFriedmann; Einstein; de Sitter ….The New CosmologyInflation - scalar fieldsThe Hot Big BangStructure Formation
7The Friedmann Model Scale factor R(t) mass density and curvature of spaceproblemshorizonflatness
8Inflationary Cosmology In the beginning there was the field….Vector, tensor and scalar fieldsWeinberg-Salaam:unified theory - the Higgs fieldThe “inflaton”central to inflationsolves the old problemspredicts a flat universe =1quantum fluctuations structure formation
9The Hot Big Bang The cosmic kitchen Abundance of “baryons” Relics big bang nucleosynthesisAbundance of “baryons”baryons ~ 0.02Relicscosmic backgroundneutrinos
10Structure Formation Quantum fluctuations gravitational instability dark matterthe “cosmic web”
27What is the Matter? Neutrinos? Axions or other fields? WIMPs? No longer popularAxions or other fields?WIMPs?Etc etc etc….Plenty of theory - scarce observations
28Dark Energy Consensus model: ~ 0.3 CMB = 1 resolution: the accelerating Universeexpansion history from supernovaefainter than expecteduniverse is being accelerated - dark energy“late time inflation” - yet another field?
31The Current Status of Cosmology A “working model” for creation of the Universe and the structure thereinImpressive concordance with current observationsEmbarrassing number of ingredientsluminous baryons; dark baryons; neutrinos; dark matter; dark energy….Epicycles?