Transcript Neutrino oscillations in dense neutrino media

Cosmological Aspects of
Neutrino Physics (III)
ν
Sergio Pastor (IFIC)
61st SUSSP
St Andrews, August 2006
Neutrino Physics and Cosmology
3rd lecture
Bounds on mν from CMB, LSS and other data
Bounds on the radiation content (Neff)
Future sensitivities on mν from cosmology
Effect of massive neutrinos on the
CMB and Matter Power Spectra
Max Tegmark
www.hep.upenn.edu/~max/
Neutrinos as Hot Dark Matter
Massive Neutrinos can still be subdominant DM: limits on mν
from Structure Formation (combined with other cosmological
data)
How to get a bound (measurement) of
neutrino masses from Cosmology
Fiducial cosmological model:
(Ωbh2 , Ωmh2 , h , ns , τ, Σmν )
DATA
PARAMETER
ESTIMATES
Cosmological Data
• CMB Temperature: WMAP plus data from other
experiments at large multipoles (CBI, ACBAR, VSA…)
• CMB Polarization: WMAP,…
• Large Scale Structure:
* Galaxy Clustering (2dF,SDSS)
* Bias (Galaxy, …): Amplitude of the Matter P(k)
(SDSS,σ8)
* Lyman-α forest: independent measurement of
power on small scales
* Baryon acoustic oscillations (SDSS)
Bounds on parameters from other data: SNIa (Ωm),
HST (h), …
Cosmological Parameters: example
SDSS Coll, PRD 69 (2004) 103501
Cosmological bounds on neutrino mass(es)
A unique cosmological bound on mν DOES NOT exist !
ν
Cosmological bounds on neutrino mass(es)
A unique cosmological bound on mν DOES NOT exist !
Different analyses have found upper bounds on neutrino
masses, since they depend on
• The combination of cosmological data used
• The assumed cosmological model: number of parameters
(problem of parameter degeneracies)
• The properties of relic neutrinos
Cosmological bounds on neutrino masses using WMAP1
Bound on Σmν (eV) [95% CL]
Ichikawa et al, PRD 71 (2005) 043001
Sánchez et al, MNRAS 366 (2006) 189
MacTavish et al, astro-ph/0507503
Hannestad, JCAP 0305 (2003) 004
SDSS Coll., PRD 69 (2004) 103501
Barger et al, PLB 595 (2004) 55
Crotty et al, PRD 69 (2004) 123007
Rebolo et al, MNRAS 353 (2004) 747
Fogli et al. PRD 70 (2004) 113003
Seljak et al, PRD 71 (2005) 103515
Sánchez et al, MNRAS 366 (2006) 189
MacTavish et al, astro-ph/0507503
WMAP Coll., ApJ Suppl 148 (2003) 175
Fogli et al. PRD 70 (2004) 113003
Seljak et al, PRD 71 (2005) 103515
MacTavish et al, astro-ph/0507503
Hannestad, hep-ph/0409108
1.6 - 3.1
Data used
CMB only
0.64 00..39
28
1.0 - 1.7
[0.6-1.2]
WMAP1, other CMB,
2dF/SDSS-gal
[HST,SNIa]
0.42-0.68
WMAP1, other CMB,
2dF/SDSS-gal,
2dF/SDSS-bias
and/or Ly-α
Cosmological bounds on neutrino masses using WMAP3
Bound on Σmν (eV) [95% CL]
WMAP Coll., astro-ph/0603449
Fukugita et al, astro-ph/0605362
Kristiansen et al, astro-ph/0608017
WMAP Coll., astro-ph/0603449
Goobar et al, astro-ph/0602155
Goobar et al, astro-ph/0602155
Seljak et al, astro-ph/0604335
Kristiansen et al, astro-ph/0608017
1.7 – 2.3
0.68 – 0.91
0.64 00..39
28
0.17-0.48
Data used
CMB only
WMAP3, other
CMB, 2dF/SDSSgal, SNIa
WMAP3, other
CMB, 2dF/SDSSgal, SDSS-BAO
and/or Ly-α
Fogli et al., hep-ph/0608060
Neutrino masses in 3-neutrino schemes
CMB + galaxy clustering
+ HST, SNI-a…
+ BAO and/or bias
+ including Ly-α
Fig from Strumia & Vissani, NPB726(2005)294
Tritium  decay, 02 and Cosmology
Fogli et al.,
hep-ph/0608060
02 and Cosmology
Fogli et al., hep-ph/0608060
Parameter degeneracy: Neutrino mass and w
In cosmological models with more parameters the neutrino mass
bounds can be relaxed.
Ex: quintessence-like dark energy with ρDE=w pDE
Λ
WMAP Coll, astro-ph/0607101
Relativistic particles in the Universe
At T<me, the radiation content of the Universe is
Effective number of relativistic neutrino species
Traditional parametrization of the energy density
stored in relativistic particles
Extra relativistic particles
• Extra radiation can be:
scalars, pseudoscalars, sterile neutrinos (totally or partially
thermalized, bulk), neutrinos in very low-energy reheating
scenarios, relativistic decay products of heavy particles…
• Particular case: relic neutrino asymmetries
Constraints on Neff from BBN and from CMB+LSS
Effect of Neff at later epochs
• Neff modifies the radiation content:
• Changes the epoch of matter-radiation equivalence
CMB+LSS: allowed ranges for Neff
• Set of parameters: ( Ωbh2 , Ωcdmh2 , h , ns , A , b , Neff )
• DATA: WMAP + other CMB + LSS + HST (+ SN-Ia)
• Flat Models
Neff  3.5
3.3
2.1
95% CL
Crotty, Lesgourgues & SP, PRD 67 (2003)
Non-flat Models
2.0
Neff  4.11.9
3.0
Neff  4.02.1
Hannestad, JCAP 0305 (2003)
Pierpaoli, MNRAS 342 (2003)
95% CL
• Recent result
2.7  Neff  4.6
95% CL
Hannestad & Raffelt, astro-ph/0607101
Future bounds on Neff
• Next CMB data from WMAP and PLANCK (other CMB
experiments on large l’s) temperature and polarization spectra
• Forecast analysis in ΩΛ=0 models
PLANCK
WMAP
Lopez et al, PRL 82 (1999) 3952
Future bounds on Neff
Updated analysis:
Larger errors
Bowen et al 2002
ΔNeff ~ 3 (WMAP)
ΔNeff ~ 0.2 (Planck)
Bashinsky & Seljak 2003
The bound on Σmν depends on the
number of neutrinos
• Example: in the 3+1 scenario, there are 4 neutrinos
(including thermalized sterile)
Abazajian 2002, di Bari 2002
• Calculate the bounds with Nν > 3
WMAP + Other CMB + 2dF + HST + SN-Ia
3ν
4ν
Hannestad JCAP 0305 (2003) 004
95% CL
5ν
Hannestad
(also Elgarøy & Lahav, JCAP 0304 (2003)
004)
Σmν and Neff degeneracy
(0 eV,3)
(0 eV,7)
(2.25 eV,7)
(0 eV,3)
(0 eV,7)
(2.25 eV,7)
Analysis with Σmν and Neff free
WMAP + ACBAR + SDSS + 2dF
Hannestad & Raffelt,
JCAP 0404 (2004) 008
Crotty, Lesgourgues & SP,
PRD 69 (2004) 123007
Previous + priors (HST + SN-Ia)
2σ upper
bound on
Σmν (eV)
Analysis with Σmν and Neff free
WMAP + ACBAR + SDSS + 2dF
Crotty, Lesgourgues & SP,
PRD 69 (2004) 123007
Hannestad & Raffelt,
astro-ph/0607101
Non-standard relic neutrinos
The cosmological bounds on neutrino masses are modified if relic
neutrinos have non-standard properties (or for non-standard
models)
Two examples where the cosmological bounds do not apply
• Massive neutrinos strongly coupled to a light scalar field:
they could annihilate when becoming NR
• Neutrinos coupled to the dark energy: the DE density is a
function of the neutrino mass (mass-varying neutrinos)
Non-thermal relic neutrinos
The spectrum could be distorted after neutrino decoupling
Example: decay of a light scalar after BBN
  
* CMB + LSS data still compatible
Thermal FD spectrum
Distortion from  decay
with large deviations from a
thermal neutrino spectrum
(degeneracy NT distortion – Neff)
* Better expectations for future
CMB + LSS data, but model
degeneracy NT- Neff remains
p  /T
Cuoco, Lesgourgues, Mangano & SP, PRD 71 (2005) 123501
Future sensitivities to Σmν
When future cosmological data will be available
1. CMB (T+P) + galaxy redshift surveys
2. CMB (T+P) and CMB lensing
3. Weak lensing surveys
4. Weak lensing surveys + CMB lensing
PLANCK+SDSS
• Fisher matrix analysis: expected sensitivities assuming a
fiducial cosmological model, for future experiments with
known specifications
Fiducial cosmological model:
(Ωbh2 , Ωmh2 , h , ns , τ, Σmν ) =
(0.0245 , 0.148 , 0.70 , 0.98 , 0.12, Σmν )
Σm detectable at 2σ if
larger than
0.21 eV (PLANCK+SDSS)
0.13 eV (CMBpol+SDSS)
Lesgourgues, SP & Perotto,
PRD 70 (2004) 045016
Future sensitivities to Σmν: new ideas
weak gravitational
and
CMB lensing
lensing
No bias uncertainty
Small scales much closer
to linear regime
Tomography:
3D reconstruction
Makes CMB sensitive to
smaller neutrino masses
Future sensitivities to Σmν: new ideas
weak gravitational
and
CMB lensing
lensing
sensitivity of future
weak lensing survey
(4000º)2 to mν
sensitivity of CMB
(primary + lensing)
to mν
σ(mν) ~ 0.1 eV
σ(mν) = 0.15 eV (Planck)
σ(mν) = 0.044 eV (CMBpol)
Abazajian & Dodelson
Kaplinghat, Knox & Song
PRL 91 (2003) 041301
PRL 91 (2003) 241301
CMB lensing: recent analysis
σ(Mν) in eV for future CMB experiments alone :
Lesgourgues et al,
PRD 73 (2006) 045021
Summary of future sensitivities
Lesgourgues & SP, Phys. Rep. 429 (2006) 307
Future cosmic
shear surveys
End of 3rd lecture