Ofer%20Lahav

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• Neutrino Masses from LSS
• Neutrino Masses from the CMB
• (III) The Dark Energy Survey

• Ofer Lahav
• University College London

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Concordance Cosmology

• SN Ia
• CMB
• LSS Baryonic Oscillations
• Cluster counts
• Weak Lensing
• Integrated Sachs Wolfe
• Physical effects
• Geometry
• Growth of Structure

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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? lt 1 eV
• Mixed Dark Matter?
• Non-linear power spectrum and biasing halo
  model
• Combined cosmological observations and
  laboratory experiments

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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?

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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/0610713
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From Great Walls to Neutrino Masses
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Neutrinos decoupled when they were still
relativistic, hence they wiped out structure on
small scales k gt knr 0.026 (m? /1 eV)1/2 ?m1/2
h/Mpc
Colombi, Dodelson, Widrow 1995
CDM
WDM
CDMHDM

Massive neutrinos mimic a smaller source term
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(No Transcript)
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Neutrino properties

• The number of neutrino species Nn affects
• the expansion rate of the universe, hence BBN.
• BBN constraints Nn between 1.7 and 3 (95 CL)
• (e.g. Barger et al. 2003).
• From CMBLSSSN Ia, N? 4.21.2-1.7 (95 CL)
• (Hannestad 2005)
• We shall assume Nn 3
• Electron, muon and tau neutrinos
• Eigen states m1, m2, m3
• 112 neutrinos per cm3
• Wn h2 Mn/(94 eV)

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Neutrino Mass Hierarchy


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Absolute Masses of Neutrinos

• Based on
• measured
• squared mass
• differences
• from solar and
• atmospheric
• oscillations
• Assuming
• m1 lt m2 lt m3

E L, NJP 05

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What could cosmic probes tell us about Neutrinos
and Dark Energy?
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The Growth factor degeneracy of Neutrinos Mass
and Dark Energy

Kiakotou, Elgaroy, OL
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DP(k)/P(k) -8 Wn /Wm Not valid on useful
scales!
Kiakotou, Elgaroy, OL 2007, astro-ph 0709.0253
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Weighing Neutrinos with 2dFGRS

• Free streaming effect
• Wn/Wm lt 0.13
• Total n mass Mlt 1.8 eV
• 0.001 lt Wn lt 0.04
• (Oscillations) (2dF)
• a Four-Component Universe ?

Wn 0.05
0.01
0.00
Elgaroy , Lahav 2dFGRS team, astro-ph/0204152
, PRL
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What do we mean by systematic uncertainties?

• Cosmological (parameters and priors)
• Astrophysical (e.g. Galaxy biasing)
• Instrumental (e.g. seeing)

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Degeneracy of neutrino mass
n 0.9
n1.0
Prior 0lt Wmlt0.5
n 1.1
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Biasing vs. neutrino mass
Pg(k) b2(k) Pm(k) b(k) a log(k) c
a
---- SAM for Lgt0.75 L
Total neutrino mass
Elgaroy Lahav , JCAP, astro-ph/030389
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Weak Lensing is promising
M?
Abazajian Dodelson (2003)
also Hannestad et al. 2006
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Non-linear P(k) with massive neutrinos

• Abazajian et al. (astro-ph/0411552)
• 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

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CMB with massive ?

M? 0.3, 0.9, 1.5, 6.0 eV Fixed ?cdm 0.26
EL 2004
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Neutrinos masses and the CMB

• If znr gt zrec ?
• ?? h2 gt 0.017 (i.e. M? gt 1.6 eV)
• Then neutrinos behave like matter -
• this defines a critical value in CMB features
• Ichikawa et al. (2004 )
• from WMAP1 alone ? M? lt 2.0 eV
• Fukugita et al. (2006)
• from WMAP3 alone ? M? lt 2.0 eV

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Normalization vs neutrino mass using WMAP
alone concordance model

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Is CMB polarisation useful for neutrino mass?
Not directly, but reduces degeneracy with the
reionization optical depth

• Fukugita, Ichikawa,
• Kawasaki, OL, astro-ph/0605362

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Ratio of bulk flows with massive neutrinos ??
0.04

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Deriving Neutrino mass from Cosmology
Data Authors Mn S mi
2dF (P01) Elgaroy, OL et al.02 lt 1.8 eV
WMAPLSSSN Spergel et al. 06 lt 0.68 eV
2dF (C05)CMB Sanchez et al. 05 lt 1.2 eV
BAOCMBLSSSN Goobar et al. 06 lt 0.62 eV
Ly-? SDSS WMAP Seljak et al. 04 lt 0.17 eV
WMAP alone Ichikawa et al. 04 Fukugita et al. 06 lt 2.0 eV

All upper limits 95 CL, but different assumed
priors !
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Forecasting Neutrino mass from Cosmology

Data Authors error
High-z galaxy surveys Planck Takada et al. (2006) 0.03-0.06 eV

High-z galaxy surveys Planck Hannestad Wong (2007) 0.05 eV
SKA Planck Abdalla Rawlings(2007) 0.05 eV

Note different error definitions and assumed
priors !
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Combined Cosmology Terrestrial Experiments
Fogli et al. Hep-ph/0408045
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Combining KATRINCMB (Host, OL, Abdalla Eitel
2007) gtgt Oles talk
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Neutrinos - Summary

• Redshift surveys ( CMB) Mn lt 0.7-1.8 eV
• Ly-? ( CMBLSS) Mn lt 0.17 eV
• Within the L-CDM scenarios, subject to
• priors.
• Alternatives MDM ruled out.
• Future errors down to 0.05 eV
• using SDSSPlanck,
• and weak gravitational lensing of background
  galaxies and of the CMB.
• Resolve the neutrino absolute mass!

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Baryon Wiggles as Standard Rulers
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Imaging Surveys
proposed
moderate
5000?
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VST/VISTA
2010-2015?
proposed
moderate
DUNE
21?
20000? (space)
2012-2018?
Y.
Y. Mellier
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DUNE Dark UNiverse Explorer

• Mission baseline
• 1.2m telescope
• FOV 0.5 deg2
• PSF FWHM 0.23
• Pixels 0.11
• GEO (or HEO) orbit
• Surveys (3-year initial programme)
• WL survey 20,000 deg2 in 1 red broad band, 35
  galaxies/amin2 with median z 1, ground based
  complement for photo-zs
• Near-IR survey (J,H). Deeper than possible from
  ground. Secures z gt 1 photo-zs
• SNe survey 2 x 60 deg2, observed for 9 months
  each every 4 days in 6 bands, 10000 SNe out to z
  1.5, ground based spectroscopy

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Photometric redshift

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

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Training on 13,000 2SLAQGenerating with
ANNz Photo-z for 1,000,000 LRGs MegaZ-LRG
?z 0.046
Collister, Lahav, Blake et al., astro-ph/0607630
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Baryon oscillations
Blake, Collister, Bridle Lahav
astro-ph/0605303
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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 deg2 g, r, i, z
• 40 deg2 repeat (SNe)
• Build new 3 deg2 camera
• and data management system
• Survey 2010-2015 (525 nights)
• Response to NOAO AO

Blanco 4-meter at CTIO
300,000,000 photometric redshifts
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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
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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 RD. (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.

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DES Forecasts Power of Multiple Techniques

w(z) w0wa(1a) 68 CL
Assumptions Clusters ?80.75, zmax1.5, WL
mass calibration BAO lmax300 WL
lmax1000 (no bispectrum) Statisticalphoto-z
systematic errors only Spatial curvature,
galaxy bias marginalized, Planck CMB
prior Factor 4.6 improvement over Stage II

DETF Figure of Merit inverse area of ellipse

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DES z0.8 photo-z shell
Mn?? ?
0.0 eV 0.4 0.9 1.7
Back of the envelope improved by sqrt (volume)
gt Sub-eV from DES (OL, Abdalla, Black in prep)
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DES and a Dark Energy Programme

• 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

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Some Outstanding Questions

• Vacuum energy
• (cosmological constant, w -1.000 after
  all ?)
• Dynamical scalar field ?
• Modified gravity ?
• Why ??/?m 3 ?
• Non-zero Neutrino mass lt 1eV ?
• The exact value of the spectral index n lt
  1 ?
• Excess power on large scales ?
• Is the curvature zero exactly ?