Relic - PowerPoint Presentation

Slide1

Relic

Neutrinos

, thermal axions and cosmology in early 2014

Elena Giusarma

arXiv:1403.4852

Based on work in collaboration with:

E. Di Valentino, M. Lattanzi, A. Melchiorri, O. MenaSlide2

Outline

Cosmological

neutrino

mass implicationsExistence of extra hot relic components as dark radiation relics, steriles

neutrino species and/or thermal

axions

Cosmological

data used

in

our

numerical

analysis

Neutrino

mass

bounds

in

different

cosmological

scenarios

Impact

of BICEP2

measurements

for

the

relativisitc

degrees

of

freedom

and neutrino

masses

ConclusionsSlide3

I

n

the

stanard cosmology hot, thermal relics are identified with the three light, active neutrino flavours of the Standard Model of elementary particles. Neutrino masses have an impact in the different cosmological observable:CMB: a) Early Integrated Sachs Wolfe effect.

The transition from the relativistic to the non relativistic neutrino regime affect the decays of the gravitational potentials at decoupling period (especially near the first acoustic peak). b) Suppression of lensing potential (with Planck).LSS: Suppression of structure formation on scales smaller than the free streaming scale when neutrinos turn non relativistic

.

Planck+WMAP

9-polarization data:

Planck+WMAP 9-polarization +HST data

:

(M.

Tegmark

)

Planck+WMAP

9-polarization +HST+BAO data:

(Ade et al ‘13 Planck Collaboration )

∑m

ν

<1.11 eV at 95% CL

∑m

ν

<0.21 eV at 95% CL

∑m

ν

<0.26 eV at 95% CLSlide4

Massless sterile neutrino species:

e.g. extra degrees of freedom produced by the annihilation of asymmetric Dark Matter

Extra

steriles massive neutrino species: motivated by the so-called neutrino oscillation anomaliesThermal axion: motivated by the strong CP problemCandidates for extra hot relic components

These extra species

Have

an associated

free streaming scales

,

reducing

the

growth

of

matter

fluctuations

at small scales

Contribute to the effective

number of relativistic degrees

of freedom

Neff

N

eff= 3.046+ΔN

eff

Slide5

Data1

CMB

:

Planck temperature anisotropies, including lensing potential WMAP 9-year polarizationACT and SPT measurements at small scalesB-mode polarization measurements

from BICEP2 Large scale structure:

SDSS Data Release 76-degree Field Galaxy Survey

New BOSS Data Release 11

WiggleZ

survey

(the full

shape

of the

matter

power spectrum and the geometrical BAO information )

Baryon

Acoustic

Oscillation (BAO) data Slide6

Data2

σ

8

measurements:CFHTLens surveyPlanck Sunyaev-Zeldovich cluster catalogBig Bang Nucleosynthesis light elements abundance:

Hubble constant measurements:

Hubble Space TelescopeSlide7

Cosmological

parameters

ΛCDM model with 3 massive neutrino species:

Extra Radiation Component at the BBN

period

2. ΛCDM

model with 3 massive neutrino

species

and

thermal

axion

:

3. ΛCDM

model with 3 massive neutrino and ΔNeff

massless dark

radiation species:Slide8

4.

ΛCDM

model

with 3 active massive neutrinos plus ΔNeff massive steriles neutrino species:Cosmological parametersTs , Tν

current temperature of the sterile and active neutrino species.

ms real mass of sterile neutrino

species

.

UNIFORM PRIORS for the cosmological parameters:

N

eff

priors

refer

to

the massless (

massive) case

ΔN

eff=Neff-3.46=(Ts

/Tν )4Slide9

Main

Results

(1)68% and 95% CL allowed regions in the (∑mν, H0) and in the (∑mν, σ8

) planeThe

allowed neutrino mass regions are displaced after considering Planck cluster data and a non zero

value on ∑

mν

is

favoured

.

ΛCDM

model

with 3 massive neutrino

species:CMB+DR11+BAO+HST:

CMB+DR11+BAO+HST+SZ Cluster:

CMB+DR11+BAO+HST+CFHTLens:

The addition of the constraints on

σ

8

and

Ω

m

from the

CFHTLens

survey

displaces

the

bounds

on the neutrino mass to

higher

values.

Giusarma

et al arXiv:1403.4852Slide10

Main

Results

(2) 68% and 95% CL allowed regions in the (∑mν, ma) plane for different combinations of data

Only with Planck SZ cluster data a

non zero value of axion mass is

favoured

at

the

2.2

σ

No evidence

for non-zero

neutrino masses

nor for non-zero

axion

mass.

2. ΛCDM

model with 3 massive neutrino

species and

thermal axion:

CMB+DR11+WZ+HST+SZ Cluster:CMB+DR11+BAO+HST+SZ Cluster:

Evidence for neutrino mass of 0.2

eV

at 3

σ

on only for one

case

Giusarma

et al arXiv:1403.4852Slide11

Main

Results

(3) 68% and 95% CL allowed regions in the (∑mν, Neff) and in the (Neff, H0 ) plane

The prior on the value of the Hubble constant from HST increases the mean value on

Neff3. ΛCDM

model with 3 massive neutrino and

ΔNeff=N

eff

-3.46

massless

dark

radiation

species:

CMB+DR11+WZ+HST+BBN (Cooke et al.):

NO EVIDENCE FOR

N

eff >3

CMB+DR11+WZ+HST+BBN (Iocco et al.): EVIDENCE FOR N

eff

>3

Giusarma

et al arXiv:1403.4852Slide12

Main

Results

(4) 4. ΛCDM model with 3 active massive neutrinos plus ΔNeff massive steriles neutrino species:68% and 95% CL allowed regions in the (∑mν

, Neff) and in the (∑mν,

mseff) plane

The bound on

N

eff

(

∑

m

ν

) is slightly

larger (more stringent)

than in massless

sterile neutrino

scenario

due to the

degeneracy with

m

s

eff

NO SIGNIFICANT PREFERENCE FOR

N

eff

>

3

CMB+DR11+WZ+HST+BBN(

Cooke

et al.):

CMB+DR11+WZ+HST+BBN(

Iocco

et al.)

:

SIGNIFICANT

PREFERENCE FOR

N

ef

f

>3

Giusarma

et al arXiv:1403.4852Slide13

BICEP2

measurem

en

tsBICEP2: detection at about 5.9σ for B-mode polarization on large scales

at 68% CLAde et al ‘14 BICEP2 Collaboration

Apparent tension with Planck+WP

limit

: r

<0.11

at

95% clSlide14

What

is

the impact of BICEP2 measurements on neutrino properties

?ΛCDM +r model with

1 massive neutrino (0.06 eV) and ΔNeff=Neff-3.046

massless

dark radiation

species

:

ΛCDM +r model

with 3 massive neutrino:

Evidence for

N

eff>3 but no

indication for neutrino masses

Extra relativistic

component

seems to solve the tension between

the Planck and BICEP2 experiments

on

r

Giusarma

et al arXiv:1403.4852

r = 0.15±0.04 at 68% CLSlide15

Conclusions

Constraints

on the

masses of the different thermal relics in different scenarios using the most recent comological dataIn the minimal three active massive neutrino scenario we found that CFHTLens

survey displaces the bound on neutrino masses to higher value. Planck cluster data favours

a non zero value on ∑mν

of

about 0.3

eV

at

4

σ

.

In the scenario with

thermal

axions and active massive neutrino species

we found

that

o

nly considering the Planck SZ cluster data plus CMB+DR11+ BAO+HST there exists a prefernce

for axion mass of 0.6 eV

at

the

obout

2.2

σ

and

only

combining Planck SZ

cluster data with CMB+DR11+ WZ+HST there is an

evidence for

neutrino mass

of 0.2

eV

at about 3σ.

In the scenario

with

massive neutrinos and

ΔN

eff

dark

radiation

species

the

bounds

on

∑

m

ν

are

less

stringent

.

BBN

constraints

reduce

both

mean

value

and the

errors

ok

N

eff

significantly

.

Considering

B-

mode

polarization

measurements

by

BICEP2

experiment

+

Planck+WP

data,

we

found

that

an

extra

realivistic

component

could

solve

the

tension

between

the

two

experiments

on

the

amplitude

of tensor

mode

.