NEUTRINOS IN COSMOLOGY

STEEN HANNESTAD UNIVERSITY OF AARHUS

ERICE, 17 SEPTEMBER 2005

e

NEUTRINOS, THE MICROWAVE BACKGROUND,AND LARGE SCALE STRUCTURE

WMAP 1-YEAR DATA

BOOMERANG 2003 FLIGHT – PUBLISHED DATA IN JULY 2005

ASTRO-PH/0507494

2dF Galaxy redshift survey15 May 2002

0.5 1.0 1.5 2.0 2.5

Billion lightyears

Red

shift

0.1

0.

2

0.3

SDSS SURVEY

2dF POWER SPECTRUM

SDSS POWER SPECTRUM

DATA FROM THE LYMAN-ALPHA FOREST PROVIDES AN INDEPENDENT MEASUREMENT OF POWER ON SMALL SCALES, BUT IN THE SEMI-LINEAR REGIME (CROFT ET AL. 2002, MCDONALD ET AL. 2003). THE RELIABILITY OF THE INFERRED MATTER SPECTRUM IS CONTROVERSIAL!

CROFT ET AL. DATA

SDSS

EXPERIMENTAL QUESTIONS FROM NEUTRINO PHYSICS

NEUTRINO MASS HIERARCHY AND MIXING MATRIX - solar & atmospheric neutrinos- supernovae

ABSOLUTE NEUTRINO MASSES- cosmology: CMB and large scale structure- supernovae

STERILE NEUTRINOS (LEPTOGENESIS)- cosmology, supernovae

NUMBER OF RELIC NEUTRINOS / RELATIVISTIC ENERGY

- cosmology

Araki et al. hep-ex/0406035

STATUS OF 1-2 MIXING (SOLAR + KAMLAND)

STATUS OF 2-3 MIXING (ATMOSPHERIC + K2K)

Maltoni et al. hep-ph/0405172

Normal hierarchy Inverted hierarchy

If neutrino masses are hierarchical then oscillation experimentsdo not give information on the absolute value of neutrino masses

However, if neutrino masses are degenerate

no information can be gained from such experiments.

Experiments which rely on the kinematics of neutrino massare the most efficient for measuring m0 (or 0 decays)

catmospherimm 0

SOLAR KAMLAND

ATMO. K2K

Tritium decay endpoint measurements have reached limitson the electron neutrino mass

This translates into a limit on the sum of the three mass eigenstates

(95%) eV 3.22/1

22 iei mUm

e

eV 7im

Mainz experiment, final analysis (Kraus et al.)

THE ABSOLUTE VALUES OF NEUTRINO MASSESFROM COSMOLOGY

NEUTRINOS AFFECT STRUCTURE FORMATIONBECAUSE THEY ARE A SOURCE OF DARK MATTER

HOWEVER, eV NEUTRINOS ARE DIFFERENT FROM CDM BECAUSE THEY FREE STREAM

1eVFS Gpc 1~ md

SCALES SMALLER THAN dFS DAMPED AWAY, LEADS TOSUPPRESSION OF POWER ON SMALL SCALES

eV 932

mh

mP

P

8

BY MEASURING THEMATTER POWER SPECTRUM

)()()( 0 kTkPkP

T(k) = Transfer functionIT IS POSSIBLE TO OBTAINCONSTRAINTS ON m

ROUGHLY ONE FINDS THAT

EISENSTEIN, HU & TEGMARK ’99

0.3 eV

1 eV

0 eV

m eV m eV

m eV m eVMa ’96

WHILE NEUTRINO MASSES HAVE A PRONOUNCED INFLUENCE ONTHE MATTER POWER SPECTRUM ON SCALES SMALLER THAN THEFREE-STREAMING SCALE THERE IS ONLY A VERY LIMITED EFFECTON THE CMB

COMBINED ANALYSIS OF CMB, 2dF AND LY-ALPHA DATA BY THEWMAP TEAM (Spergel et al. 2003)

A SELECTION OF RECENT RESULTS ON m

WMAP ONLY 13 eV @ 95% WMAP

SPERGEL ET AL. (WMAP) 2003

0.69 eV @ 95% WMAP, CMB, 2dF, H0

STH 2003 1.01 eV @ 95% WMAP, CMB, 2dF, H0

ALLEN, SMITH, BRIDLE 2003

eV @ 68% WMAP, CMB, 2dF, H0

TEGMARK ET AL 2003

1.8 eV @ 95% WMAP, SDSS

BARGER ET AL 2003

0.65 eV @ 95% WMAP, CMB, 2dF, SDSS H0

CROTTY ET AL. 2004

1.0 eV @ 95% WMAP, CMB, 2dF, SDSS H0

STH 2005 1.5 eV @ 95% WMAP, SDSS,

SNI-A, H0

3.026.056.0

ANALYSIS WITH RECENT DATA:WMAP CMB DATASDSS LARGE SCALE STRUCTURE DATARIESS ET AL. SNI-a ”gold” SAMPLE Ly DATA FROM KECK SAMPLE, NO PRIOR ON 8 (SMALL SCALE AMPLITUDE)

STH, HEP-PH/0409108

C.L. 95% @ eV 65.0 m

BOUND FROM SDSS + WMAP + BIAS + SDSS LYMAN ALPHA(SELJAK ET AL. ASTRO-PH/0407372)

C.L. 95% @ eV 42.0 m

FOGLI ET AL. HEP-PH/0408045 FIND ~ 0.5 eV IN A SIMILAR STUDY

BOTH RESULTS RELY ON THE ABILITY TO MEASURE THEEXACT MATTER FLUCTUATION AMPLITUDE ON SMALLSCALES

GENERAL HEALTH WARNING

A GENERIC PROBLEM WITH USING COSMOLOGICAL OBSERVATIONSTO PROBE PARTICLE PHYSICS:

IN GENERAL, LIKELIHOOD ANALYSES ARE CARRIED OUT ON TOPOF THE MINIMAL COSMOLOGICAL STANDARD MODEL

HOWEVER, THERE COULD BE MORE THAN ONE NON-STANDARDEFFECT, SEVERELY BIASING THE PARAMETER ESTIMATE

ANY DERIVED LIMIT SHOULD BE TREATED WITH SOME CARE!

STH, ASTRO-PH/0505551

EXAMPLE:

THERE IS A VERY STRONG DEGENERACY BETWEEN NEUTRINOMASS AND THE DARK ENERGY EQUATION OF STATE

w ALLOWED TO VARY

w KEPT FIXED

m ALLOWED TO VARY

m KEPT FIXED

THE STRONG m-w DEGENERACY OCCURS BECAUSE OF M

WHEN m INCREASES, M MUST ALSO INCREASE TO PRODUCETHE SAME MATTER SPECTRUM.

FOR w = -1 THIS QUICKLY BECOMES INCOMPATIBLE WITH SNI-ADATA, BUT NOT IF w IS ALLOWED TO VARY FREELY

KNOP ET AL. ASTRO-PH/0309368 (SCP)

EXPERIMENTAL QUESTIONS FROM NEUTRINO PHYSICS

NEUTRINO MASS HIERARCHY AND MIXING MATRIX - solar & atmospheric neutrinos- supernovae

ABSOLUTE NEUTRINO MASSES- cosmology: CMB and large scale structure- supernovae

STERILE NEUTRINOS (LEPTOGENESIS)- cosmology, supernovae

NUMBER OF RELIC NEUTRINOS / RELATIVISTIC ENERGY

- cosmology

ANALYSIS OF PRESENT DATAGIVES A LIMIT ON N OF

C.L.) (95% 72 N

NOTE THAT THIS MEANS APOSITIVE DETECTION OF THE COSMIC NEUTRINO BACK-GROUND AT 3.5

STH 2003 (JCAP 5, 004 (2003))

Because of the stringent bound from LEP on neutrinos lighter than about 45 GeV

008.0992.2 N

this bound is mainly of academic interest if all such light neutrinos couple to Z. However, sterile neutrinos can also contribute to N

Crotty, Lesgourgues & Pastor ’03Pierpaoli ’03, Barger et al. ’03

ANALYSIS OF ALL THE PRESENTDATA, INCLUDING BOOMERANG-03GIVES A PRESENT LIMIT OF

C.L.) (95% 2.54.2 N

THIS IS ENTIRELY COMPATIBLEWITH THE MOST RECENT 4-HEDETERMINATION

0092.02495.0 YCyburt et al. 2004 (astro-ph/0408033)

AT PRESENT THERE IS NO SIGNIFICANT BOUND ON EXTRA THERMAL RELICS, EITHER AT BBN OR AT RECOMBINATION!

STH 2005, IN PREPARATION

See also: Crotty, Lesgourgues & Pastor ’03STH ’03, Pierpaoli ’03, Barger et al. ’03

STERILE NEUTRINOS: WHAT ABOUT LSND?

TAKEN AT FACE VALUE THE WMAP RESULT ON NEUTRINO MASSSEEMS TO RULE OUT LSND BECAUSE NO ALLOWED REGIONS EXISTFOR LOW m2. (Pierce & Murayama, hep-ph/0302131; Giunti hep-ph/0302173)

WMAP

HOWEVER, A DETAILED ANALYSIS SHOWS THAT INCREASING N, THE NEUTRINO MASS, AND THE MATTER DENSITY SIMULTANEOUSLYPRODUCES EXCELLENT FITS

0 = 1.0 M= 0.3 b= 0.05 H0 = 70 ns = 1.0 m = 0 N = 3

0 = 1.0 M= 0.3 b= 0.05 H0 = 70 ns = 1.0 m = 3eV N = 3

0 = 1.0 M= 0.3 b= 0.05 H0 = 70 ns = 1.0 m = 3eV N = 8

0 = 1.0 M= 0.35 b= 0.05 H0 = 70 ns = 1.0 m = 3eV N = 8

STH, JCAP 0305, 004 (2003), STH & G RAFFELT JCAP 0404, 008 (2004)

THE UPPER MASS LIMIT ON EACH INDIVIDUAL MASS EIGENSTATEIS ROUGHLY CONSTANT FOR ALL N IF ALL SPECIES CARRY EQUALMASS

STH & G RAFFELT (JCAP 0404, 008 (2004))SEE ALSO CROTTY, LESGOURGUES & PASTOR HEP-PH/0402049

Maltoni, Schweitz, Tortola & Valle ’03 (hep-ph/0305312)ONLY IF LYMAN-ALPHA AND BIAS CONSTRAINTS ARE INCLUDED ISTHE LSND SOLUTION EXCLUDED AT 95% C.L. (SELJAK ET AL. 2004)

A GLOBAL ANALYSIS STILL LEAVES THE TWO LOWEST LYING ISLANDSIN PARAMETER SPACE FOR LSND!

WHAT ABOUT OTHER LIGHT, THERMALLYPRODUCED PARTICLES?

NEUTRINOS

AXIONS

GRAVITONS

MAJORONS

AXINOS

RADIONS

...........

FOR ANY THERMALLY PRODUCED PARTICLE IT ISSTRAIGHTFORWARD TO CALCULATE THE DECOUPLINGEPOCH ETC.THE ONLY IMPORTANT PARAMETERS ARE

Xm

WHERE g* IS THE EFECTIVE NUMBER OF DEGREES OFFREEDOM WHEN X DECOUPLES.

*,XgAND

bosonsfor 3/4

fermionsfor 175.10

eV 183 *

2

X

XXX g

gmh

2

24

2X

FS 9.3log1Mpc 20

~Xm

XX

T

T

T

T

h

CONTRIBUTION TO DENSITY

FREE-STREAMING LENGTH

EW transition (~ 100 GeV)g* = 106.75

Density bound for a Majorana fermion

STH, hep-ph/0409108 (See also STH & G Raffelt, JCAP 0404, 008)Similar bound can be obtained for pseudoscalars (such a axions) – STH, Mirizzi & Raffelt 2005

Based on WMAP, SDSS, SNI-a and Lyman- data, No assumptions about bias!

MASS BOUND FOR SPECIES DECOUPLINGAROUND EW TRANSITION

eV 5m

DECOUPLING AFTERQCD PHASE TRANSITIONLEADS TO

eV 1m

Below QCD transition (~ 100 MeV) g* < 20

NOTE THAT MASS BOUNDS CANNOT BE DIRECTLY EXTENDEDTO RELIC PARTICLES WHICH MAKE UP MORE THAN A SMALLFRACTION OF THE TOTAL DENSITY!!

LYMAN-ALPHA ANALYSIS IS BASED ON THE ASSUMPTION THATTHE POWER SPECTRUM IS CLOSE TO A POWER-LAW

IF THERE IS EXPONENTIAL DAMPING THEN THE ”RAW” LYMAN-ALPHA DATA SHOULD BE USED DIRECTLY AND COMPAREDWITH NUMERICAL SIMULATIONS

THIS HAS BEEN DONE BY VIEL ET AL. astro-ph/0501562

VIEL ET AL. astro-ph/0501562

THE 2LOWER BOUND ON THE MASS OF THE WDM PARTICLE IS ~ 500 eV

THE BEST FIT IS NOT ATINFINITE MASS ALTHOUGHTHE EFFECT IS NOT STATISTICALLY SIGNIFICANT

WHAT IS IN STORE FOR THE FUTURE?

LARGE SCALE STRUCTURE SURVEYS2dF (completed) 250.000 galaxies SDSS (ongoing) 1.000.000 galaxies

COSMOLOGICAL SUPERNOVA SURVEYSSNLS, DARK ENERGY CAMERA, SNAP

WEAK LENSING SURVEYS (Pan-STARRS 2006, LSST 2012)

BETTER CMBR TEMPERATURE MEASUREMENTS

Satellites Balloons InterferometersWMAP (ongoing) Boomerang (2002-2003) CBI (ongoing)Planck (2007) TopHat (ongoing) DASI (ongoing)

CMBR POLARIZATION MEASUREMENTS

Satellites Balloons GroundWMAP (ongoing) Boomerang (2002-3) Polatron (ongoing)Planck (2007) DASI

CMB POLARIZATION ANISOTROPY MEASUREMENT

Tlm

Elm

ETl aaC *

),(),(),( ,, Bablm

Blm

lm

Eablm

Elm

ab YaYaT

P

Gives a new sequence ofpower spectra

Elm

Elm

EEl aaC *

Blm

Blm

BBl aaC *

Dodelson & Hu ’01

PROJECTED OBSERVATIONAL ERRORS FOR MAP AND PLANCK

WMAP FINAL DATA (4 YEARS) PLANCK (STARTING 2007)

SNAP SATELLITE

http://snap.lbl.gov

THE SUPERNOVAACCELERATIONPROBE (SNAP) WILLOBSERVE ROUGHLY2000 TYPEI-a SN OUTTO REDSHIFTS OFORDER 1.5, STARTINGFROM ~ 2012?

Distortion of background images by foreground matter

Unlensed Lensed

WEAK LENSING – A POWERFUL PROBE FOR THE FUTURE

H

drPa

gHC m

0

2

240 ),/(

)(

16

9

H

dng

0

''

)'()'(2)(

FROM A WEAK LENSING SURVEY THE ANGULAR POWER SPECTRUMCAN BE CONSTRUCTED, JUST LIKE IN THE CASE OF CMB

),/( rP MATTER POWER SPECTRUM (NON-LINEAR)

WEIGHT FUNCTION DESCRIBING LENSINGPROBABILITY

(SEE FOR INSTANCE JAIN & SELJAK ’96, ABAZAJIAN & DODELSON ’03,SIMPSON & BRIDLE ’04)

Non-linear physics

Wide survey

WEAK LENSING POWER SPECTRUM

FIRST PROJECT Pan-STARRS WILL START IN JANUARY 2006

MASS BOUNDS ON LIGHT PARTICLESWILL IMPROVE SIGNIFICANTLY IN THE FUTURE, PERHAPS EVEN TO 0.1 eVFOR THE SUM OF NEUTRINO MASSES