The Standard Model of Cosmology Avishai Dekel, HUJI, PANIC08

North Galactic Hemisphere Lick Survey 1M galaxies isotropy→homogeneity North Galactic Hemisphere

Microwave Anisotropy Probe February 2003, 2004 WMAP Science breakthrough of the year δT/T~10-5 isotropy→homogeneity

Homogeneity & Isotropy - Robertson-Walker Metric comoving radius angular area expansion factor

kinetic potential curvature vacuum Friedman Equation Homogeneity + Gravity ( )  kinetic potential curvature vacuum Two basic free parameters closed/open decelerate/accelerate

Solutions of Friedman eq. matter era, Λ=0 acceleration expansion forever conformal time collapse big bang here & now

Dark Matter and Dark Energy vacuum – repulsion? 1 decelerate accelerate m /2 - =0 open closed flat m + =1  bound unbound =0 EdS 1 2 m mass - attraction

Luminous Matter 3

Spiral galaxy M74

Elliptical Galaxy

שביל החלב בצבעים

Luminous mass all sources, all wavelengths With Λ=0, Universe unbound and infinite?

Dark Matter 4

Measuring Dark Matter Disk galaxies: rotation curves Clusters and Elliptical galaxies: virial theorem All scales: gravitational Lensing Clusters: X-ray Clusters: scattering of CMB by gas Large-Scale: cosmic flows Large-Scale: power-spectrum of density fluctuations Cluster abundance at early times

Dark-Matter Halos in Galaxies 30,0000 ly dark halo v R flat rotation curve v R 3,000light years

Flat Rotation Curves: Extended Massive Dark-Matter Halos in Disk Galaxies Milky Way Sofue & Rubin 2001

dark-matter halo The Cosmic Web of Dark Matter the millenium cosmological simulation

Virial Equilibrium in Clusters of Galaxies  M~7x1014 M V~1500 km/s R~1.5 Mpc

Gravitational Lensing: Dark Matter in Galaxy Clusters HST

Gravitational Lensing

Observed Radial Peculiar Velocities Mark III

POTENT: Cosmic Flows Observe radial peculiar velocities: Potential flow: Smooth the radial velocity field. Integrate from the origin along radial trajectories to obtain the potential at any point in space. Differentiate to obtain the 3-dimensional velocity field. Compute density-fluctuation field by another differentiation:

Large-Scale Cosmic Flows - POTENT Great Attractor

Dark-Matter Density us 200 Mpc Supergalactic Plane

Mass Density in 3D 3D dark-matter density Great Attractor Perseus Pisces Great Void

Matter Density from Void Outflows Dekel & Rees 1993 ρ=0 δ=-1 high Ωm low Ωm rees/void21.gif

2dF Pk Measuring m from the 2dF Survey power spectrum 2dF Pk Measuring m from the 2dF Survey 2D correlation function angular separation redshift anisotropy in z-space

Total Mass What is the dark matter made of? exerting gravitational attraction With Λ=0, Universe still unbound and infinite? What is the dark matter made of?

Baryonic dark matter: planets, black holes, … Baryonic Mass Baryonic dark matter: planets, black holes, … Big-Bang Nucleosynthesis:

Big Bang Nucleosynthesis only 12.5% n left after decaying to p  75% H + 25% He (in mass) At T~109K deuterium becomes stable and nucleosynthesis starts: A minute later p becomes too cold to penetrate the Coulomb barrier by p in d and the process stops. Rate  np2  abundances of d and 3He decrease with b b=0.04  0.01 bh2=0.02

Non-Baryonic Dark-Matter Particles Neutralinos, photinos, axions, ... all those damn super-symmetric particles you can’t see… that’s what drove me to drink… but now I can see them!

Dark Matter and Dark Energy 1 accelerate decelerate  unbound bound EdS LSS closed open flat 1 2 m

measure the expected deceleration under gravitational attraction Dark Energy measure the expected deceleration under gravitational attraction 8

The Telescope as a Time Machine young billions of light-years old 2 millions of light-years  age of universe (Gyr)  13.69 13.7 looking far → back in time

Hubble Deep Field

Supernova: Crab

Bright Standard Candle: Supernovae Type Ia

Luminosity-distance to a standard candle magnitude = -2.5 log (luminosity) +const. Luminosity distance (DL=dLH0) Observe a sample of z-m Determine M and H0 at low z Find Ωm and ΩΛ by best fit at high z

Today’s expansion rate V=H0R Deceleration? distance R nearby supernovae רחוק V velocity V היקום מאיץ

Acceleration! Past expansion rate V=H(t) R R V distance nearby far away Saul Brian Perlmutter Schmidt velocity V היקום מאיץ

Acceleration by a cosmological constant Big Bang here & now time

Acceleration Vacuum Energy 25

Dark Matter and Dark Energy SN 1 accelerate decelerate  unbound bound EdS LSS flat closed open 1 2 m

Curvature 11

Use a Standard Ruler known intrinsic length flat curved observed angle

Cosmic Microwave Background time

Origin of Cosmic Microwave Background horizon big-bang t=0 last-scattering surface Thomson scattering trec~380 kyr T~4000K ct0 T~2.7K c(t0-tdec) here & now t0~14 Gyr horizon at trec ~100 comoving Mpc ~1o transparent neutral H ionized p+e- opaque

Horizon at last scattering ~ 100 comoving Mpc ~ 1˚ Characteristic Scale time here & now z=0 t=13.7 Gyr space past light cone neutral H transparent last scattering z~1090 t=380 kyr ionized opaque horizon z=∞ t=0 big bang singularity Horizon at last scattering ~ 100 comoving Mpc ~ 1˚

Acoustic Peaks In the early hot ionized universe, photons and baryons are coupled via Thomson scattering off free electrons. Initial fluctuations in density and curvature (quantum, Inflation) drive acoustic waves, showing as temperature fluctuations, with a characteristic scale - the sound horizon cst. At z~1,090, T~4,000K, H recombination, decoupling of photons from baryons. The CMB is a snapshot of the fluctuations at the last scattering surface. Primary acoustic peak at rls ~ ctls ~ 100 co-Mpc or θ~1˚ (~200) – the “standard ruler”. Secondary oscillations at fractional wavelengths.

Curvature closed flat open

Curvature closed flat open

CMB Temperature Maps isotropy T2.725K T/T~10-3 dipole WMAP 2003 COBE 1992 WMAP 2003 resolution ~10o resolution ~ 10’ T/T~10-5

WMAP: Wilkinson Microwave Anisotropy Probe δT/T~10-5 10 arcmin Charles Bennett

Angular Power Spectrum  angle =2/

Curvature 1st peak closed open flat

Curvature The Universe is nearly flat: Open? Closed? Surely much larger than our horizon!

Dark Matter and Dark Energy SN 1 open closed flat * accelerate decelerate  CMB unbound bound EdS LSS 1 2 m 40

Other Parameters: Baryons, Fluctuations

CMB Acoustic Oscillations explore all parameters compression kctls=π curvature velocity max dark matter initial conditions dissipation rarefaction kcstls=2π baryons

The ΛCDM model is very successful Accurate parameter determination curvature dark matter initial fluctuations dissipation baryons

Polarization by scattering off electrons; re-ionization by stars & quasars at z~10

Cosmic History galaxy formation dark ages big bang last scattering t=380 kyr reionization t=430 Myr today t=13.7 Gyr

Baryonic Acoustic Oscillations observed in the galaxy-galaxy correlation function (SDSS, z=0.35) D(z=0.35) is 10% of way to surface of last-scattering. Currently have a 4% measurement of s.

The Sloan Digital Sky Survey Redshifts to 1M galaxies

Success of the Standard Model: Fluctuation Power Spectrum

Success of the LCDM Power Spectum

Standard ΛCDM Model Parameters 2015: Planck (+BAO+SN) Hubble constant H0=67.8  0.9 km s-1 Mpc-1 Total density Ωm+λ = 1.000  0.005 Dark energy density ΩΛ=0.692  0.012 Mass density Ωm=0.308  0.012 Baryon density Ωb=0.0478  0.0004 Fluctuation spectral index ns=0.968  0.006 Fluctuation amplitude σ8=0.830  0.015 Optical depth =0.066  0.016 Age of universe t0=13.80  0.02 Gyr

Beyond the Standard Model 20

What is the Dark Energy? “ ‘Most embarrassing observation in physics’ – that’s the only quick thing I can say about dark energy that’s also true.” ……………………………………..Edward Witten or - Cosmological constant in GR? - Failure of GR? Quintessence? Novel property of matter? - Why so small? in cosmology 10-48 Gev4 … …vs QFT: 108 Gev4 (ElectroWeak) or 1072 Gev4 (Planck) - Why becoming dominant now? (Anthropic principle?)

Generalized Dark Energy Cosmological constant Energy conservation during expansion Equation of state Generalized eq. of state e.g. Quintessence Friedman eq. and the fluctuation growth-rate eq. probe different parts of the theory and can constrain w(t)

Equation of State and its Time Variation Very close to standard GR with a cosmological constant

Beyond the Standard ΛCDM Model 2015: Planck (+BAO+SN) Total density Ωtot = 1-Ωk = 1.001  0.004 Equation of state w = -1.006  0.045 Tensor/scaler fluctuations r < 0.11 (95% CL) Running of spectral index dn/dlnk = -0.03  0.02 Neutrino mass ∑ mν < 0.23 eV (95% CL) # of light neutrino families Neff=3.15  0.23

Neutrino Mass and # of Families

Open Questions - The Big Bang? Inflation? - What is the dark energy? - What is the dark matter particle? - How do galaxies form from the cosmic web? - How do stars form in galaxies

Conclusions - Cosmology has a Standard Model: ΛCDM - The basic parameters are accurately measured ….using multiple techniques - Mysteries: dark matter, dark energy, big-bang, ….inflation - Next step: probe physics beyond the standard ….model - Current effort: galaxy formation

Age of the oldest globular star clusters

Age of an old star cluster 12 16

The Age of the Universe