Ofer Lahav University College London (I)Neutrino Masses from LSS (I)Neutrino Masses from the CMB (III) The Dark Energy Survey

Concordance Cosmology  SN Ia  CMB  LSS – Baryonic Oscillations  Cluster counts  Weak Lensing  Integrated Sachs Wolfe Physical effects: * Geometry * Growth of Structure

Massive Neutrinos and Cosmology * Why bother? – absolute mass, effect on other parameters * Brief history of ‘Hot Dark Matter’ * Limits on the total Neutrino mass from cosmology within  CDM M < 1 eV * Mixed Dark Matter? * Non-linear power spectrum and biasing – halo model * Combined cosmological observations and laboratory experiments 

Brief History of ‘Hot Dark Matter’ * 1970s : Top-down scenario with massive neutrinos (HDM) – Zeldovich Pancakes * 1980s: HDM - Problems with structure formation * 1990s: Mixed CDM (80%) + HDM (20% ) * 2000s: Baryons (4%) + CDM (26%) +Lambda (70%): But now we know HDM exists! How much?

Globalisation and the New Cosmology  How is the New Cosmology affected by Globalisation?  Recall the Cold War era: Hot Dark Matter/top-down (East) vs. Cold Dark Matter/bottom-up (West)  Is the agreement on the `concordance model’ a product of Globalisation? OL, astro-ph/

From Great Walls to Neutrino Masses

Neutrinos decoupled when they were still relativistic, hence they wiped out structure on small scales k > k nr = (m  /1 eV) 1/2  m 1/2 h/Mpc Colombi, Dodelson, & Widrow 1995  WDMCDM+HDM CDM Massive neutrinos mimic a smaller source term

Neutrino properties The number of neutrino species N affects the expansion rate of the universe, hence BBN. BBN constraints N between 1.7 and 3 (95% CL) (e.g. Barger et al. 2003). From CMB+LSS+SN Ia, N = (95% CL) (Hannestad 2005) We shall assume N  =3 neutrinos Electron, muon and tau neutrinos Eigen states Eigen states m 1, m 2, m 3  neutrinos per cm 3   h    eV  

Neutrino Mass Hierarchy

Absolute Masses of Neutrinos Based on measured squared mass differences from solar and atmospheric oscillations Assuming m 1 < m 2 < m 3   E & L, NJP 05

What could cosmic probes tell us about Neutrinos and Dark Energy?

The Growth factor: degeneracy of Neutrinos Mass and Dark Energy Kiakotou, Elgaroy, OL

Kiakotou, Elgaroy, OL 2007, astro-ph  P(k)/P(k) = -8    m Not valid on useful scales!

Weighing Neutrinos with 2dFGRS  Free streaming effect:   /  m  < 0.13 Total mass M< 1.8 eV    (Oscillations) (2dF)  a Four-Component Universe ? Elgaroy, Lahav & 2dFGRS team, astro-ph/ , PRL   =

What do we mean by ‘systematic uncertainties’? Cosmological (parameters and priors) Astrophysical (e.g. Galaxy biasing) Instrumental (e.g. ‘seeing’)

Degeneracy of neutrino mass n= 0.9 n= 1.1 n=1.0 Prior 0<  m <0.5

Biasing vs. neutrino mass Elgaroy & Lahav, JCAP, astro-ph/ SAM for L>0.75 L* P g (k) = b 2 (k) P m (k) b(k) = a log(k) + c a Total neutrino mass

Weak Lensing is promising Abazajian & Dodelson (2003)  also Hannestad et al. 2006

Non-linear P(k) with massive neutrinos Abazajian et al. (astro-ph/ ) modeled the effects of neutrino infall into CDM halos and incorporated it in the halo model. The effect is small:  P(k)/P(k) » 1% at k » 0.5 h/Mpc for M » 1 eV Future work : high-resolution simulations with CDM, baryons and neutrinos

CMB with massive E&L 2004 E&L 2004 M =0.3, 0.9, 1.5, 6.0 eV Fixed  cdm = 0.26

Neutrinos masses and the CMB If z nr > z rec    h 2 > (i.e. M > 1.6 eV) Then neutrinos behave like matter - this defines a critical value in CMB features * Ichikawa et al. (2004 ) from WMAP1 alone  M < 2.0 eV * Fukugita et al. (2006) from WMAP3 alone  M < 2.0 eV 

Normalization vs neutrino mass using WMAP alone + concordance model

Is CMB polarisation useful for neutrino mass? Fukugita, Ichikawa, Kawasaki, OL, astro-ph/ Not directly, but reduces degeneracy with the reionization optical depth

Ratio of bulk flows with massive neutrinos  =0.04

Deriving Neutrino mass from Cosmology DataAuthors M  m i 2dF (P01)Elgaroy, OL et al.02 < 1.8 eV WMAP+LSS+SN … Spergel et al. 06 < 0.68 eV 2dF (C05)+CMBSanchez et al. 05 < 1.2 eV BAO+CMB+LSS +SN Goobar et al. 06 < 0.62 eV Ly-  + SDSS+ WMAP+… Seljak et al. 04 < 0.17 eV WMAP aloneIchikawa et al. 04 Fukugita et al. 06 < 2.0 eV All upper limits 95% CL, but different assumed priors !

Forecasting Neutrino mass from Cosmology DataAuthors error High-z galaxy surveys + Planck Takada et al. (2006) eV High-z galaxy surveys + Planck Hannestad & Wong (2007) 0.05 eV SKA + PlanckAbdalla & Rawlings(2007) 0.05 eV Note different error definitions and assumed priors !

Combined Cosmology & Terrestrial Experiments Fogli et al. Hep-ph/

Combining KATRIN+CMB (Host, OL, Abdalla & Eitel 2007) =>> Ole’s talk

Neutrinos - Summary * Redshift surveys (+ CMB) M < eV Ly-  (+ CMB+LSS)  M < 0.17 eV * Within the  -CDM scenarios, subject to priors. * Alternatives: MDM ruled out. * Future: errors down to 0.05 eV using SDSS+Planck, and weak gravitational lensing of background galaxies and of the CMB. Resolve the neutrino absolute mass!

Baryon Wiggles as Standard Rulers

Imaging Surveys Survey Sq. Degrees FiltersDepthDatesStatus CTIO751shallowpublished VIRMOS91moderatepublished COSMOS2 (space)1moderatecomplete DLS (NOAO) 364deepcomplete Subaru30?1?deep 2005? observing CFH Legacy 1705moderate observing RCS2 (CFH) 8303shallow approved VST/KIDS/ VISTA/VIKING moderate ? 50%approved DES (NOAO) 50004moderate ? proposed Pan-STARRS ~10,000?5?moderate ? ~funded LSST15,000?5?deep ? proposed JDEM/SNAP (space) 9deep ? proposed VST/VISTA DUNE 5000? ? moderate 4+5 proposed 20000? (space) 2+1? moderate ? proposed Y. Y. Mellier

DUNE: Dark UNiverse Explorer Mission baseline: 1.2m telescope FOV 0.5 deg 2 PSF FWHM 0.23’’ Pixels 0.11’’ GEO (or HEO) orbit Surveys (3-year initial programme): WL survey: 20,000 deg 2 in 1 red broad band, 35 galaxies/amin 2 with median z ~ 1, ground based complement for photo-z’s Near-IR survey (J,H). Deeper than possible from ground. Secures z > 1 photo-z’s SNe survey: 2  x  60 deg 2, observed for 9 months each every 4 days in 6 bands, SNe out to z ~ 1.5, ground based spectroscopy

Photometric redshift Probe strong spectral features (4000 break) Difference in flux through filters as the galaxy is redshifted.

*Training on ~13,000 2SLAQ *Generating with ANNz Photo-z for ~1,000,000 LRGs MegaZ-LRG  z = Collister, Lahav, Blake et al., astro-ph/

Baryon oscillations Blake, Collister, Bridle & Lahav; astro-ph/

The Dark Energy Survey Study Dark Energy using 4 complementary techniques: I. Cluster Counts II. Weak Lensing III. Baryon Acoustic Oscillations IV. Supernovae Two multi-band surveys 5000 deg 2 g, r, i, z 40 deg 2 repeat (SNe) Build new 3 deg 2 camera and data management system Survey (525 nights) Response to NOAO AO Blanco 4-meter at CTIO 300,000,000 photometric redshifts

The DES Collaboration Fermilab: J. Annis, H. T. Diehl, S. Dodelson, J. Estrada, B. Flaugher, J. Frieman, S. Kent, H. Lin, P. Limon, K. W. Merritt, J. Peoples, V. Scarpine, A. Stebbins, C. Stoughton, D. Tucker, W. Wester University of Illinois at Urbana-Champaign: C. Beldica, R. Brunner, I. Karliner, J. Mohr, R. Plante, P. Ricker, M. Selen, J. Thaler University of Chicago: J. Carlstrom, S. Dodelson, J. Frieman, M. Gladders, W. Hu, S. Kent, R. Kessler, E. Sheldon, R. Wechsler Lawrence Berkeley National Lab: N. Roe, C. Bebek, M. Levi, S. Perlmutter University of Michigan: R. Bernstein, B. Bigelow, M. Campbell, D. Gerdes, A. Evrard, W. Lorenzon, T. McKay, M. Schubnell, G. Tarle, M. Tecchio NOAO/CTIO: T. Abbott, C. Miller, C. Smith, N. Suntzeff, A. Walker CSIC/Institut d'Estudis Espacials de Catalunya (Barcelona): F. Castander, P. Fosalba, E. Gaztañaga, J. Miralda-Escude Institut de Fisica d'Altes Energies (Barcelona): E. Fernández, M. Martínez CIEMAT (Madrid): C. Mana, M. Molla, E. Sanchez, J. Garcia-Bellido University College London: O. Lahav, D. Brooks, P. Doel, M. Barlow, S. Bridle, S. Viti, J. Weller University of Cambridge: G. Efstathiou, R. McMahon, W. Sutherland University of Edinburgh: J. Peacock University of Portsmouth: R. Crittenden, R. Nichol, R. Maartnes, W. Percival University of Sussex: A. Liddle, K. Romer plus postdocs and students

The Dark Energy Survey UK Consortium (I) PPARC funding: O. Lahav (PI), P. Doel, M. Barlow, S. Bridle, S. Viti, J. Weller (UCL), R. Nichol (Portsmouth), G. Efstathiou, R. McMahon, W. Sutherland (Cambridge) J. Peacock (Edinburgh) Submitted a proposal to PPARC requesting £ 1.7M for the DES optical design. In March 2006, PPARC Council announced that it “will seek participation in DES”. PPARC already approved £220K for current R&D. (II) SRIF3 funding: R. Nichol, R. Crittenden, R. Maartens, W. Percival (ICG Portsmouth) K. Romer, A. Liddle (Sussex) Funding the optical glass blanks for the UCL DES optical work These scientists will work together through the UK DES Consortium. Other DES proposals are under consideration by US and Spanish funding agencies.

DES Forecasts: Power of Multiple Techniques Assumptions: Clusters:  8 =0.75, z max =1.5, WL mass calibration BAO: l max =300 WL: l max =1000 (no bispectrum) Statistical+photo-z systematic errors only Spatial curvature, galaxy bias marginalized, Planck CMB prior Factor 4.6 improvement over Stage II w(z) =w 0 +w a (1–a) 68% CL DETF Figure of Merit: inverse area of ellipse

DES z=0.8 photo-z shell Back of the envelope: improved by sqrt (volume) => Sub-eV from DES (OL, Abdalla, Black; in prep)   0.0 eV

* 4-5 complementary probes * Survey strategy delivers substantial DE science after 2 years * Relatively modest (~ $20-30M), low-risk, near-term project with high discovery potential * Synergy with SPT and VISTA on the DETF Stage III timescale * Scientific and technical precursor to the more ambitious Stage IV Dark Energy projects to follow: LSST and JDEM DES and a Dark Energy Programme

Some Outstanding Questions : * Vacuum energy (cosmological constant, w= after all ?) * Dynamical scalar field ? * Modified gravity ? * Why   /  m = 3 ? * Non-zero Neutrino mass < 1eV ? * The exact value of the spectral index: n < 1 ? * Excess power on large scales ? * Is the curvature zero exactly ?