Astrophysical Tests of Mirror Dark Matter

HLPW meeting – March 6-8, 2008

AstrophysicalAstrophysical teststests ofof mirrormirror darkdark mattermatter

Paolo Ciarcelluti

ULgULg IFPAIFPA

Fundamental Interactions in Physics and Astrophysics

University of Liège

HLPW 2008 Publications related to this talk

P. Ciarcelluti, Ph.D. Thesis [astro-ph/0312607].

P. Ciarcelluti, Structure formation Int. J. Mod. Phys. D 14, 187-222 (2005) [astro-ph/0409630].

P. Ciarcelluti, Cosmic Microwave Int. J. Mod. Phys. D 14, 223-256 (2005) Background [astro-ph/0409633]. and Large Scale Structure

Z.Berezhiani, P.Ciarcelluti, D.Comelli, F.Villante, Int. J. Mod. Phys. D 14, 107-120 (2005) [astro-ph/0312605]. Thermodynamics of the early Universe P. Ciarcelluti, A. Lepidi, and papers submitted and in preparation Big Bang Nucleosynthesis

P. Ciarcelluti, paper in preparation

Z.Berezhiani, P.Ciarcelluti, S.Cassisi, A.Pietrinferni, Mirror dark stars Astropart. Phys. 24, 495-510 (2006) and MACHOs [astro-ph/0507153].

HLPW 2008 MotivationMotivation ofof thisthis researchresearch search for dark matter candidates

Components of a flat Universe inin standardstandard cosmology:cosmology:

γ ν → Ω ∼ −5 Ω  radiation (relic and ) R 10 << m

→ Ω ≈  matter m 0.2-0.3

→ Ω ≅ −2 . visible (baryonic) matter b 0.02 h . dark matter (CDM, WDM, some HDM) → Ω Ω − Ω DM = m b → Ω − Ω dark energy (cosmological constant or quintessence) Λ = 1 m

HLPW 2008 MotivationMotivation ofof thisthis researchresearch search for dark matter candidates

Components of a flat Universe inin standardstandard cosmology:cosmology:

γ ν → Ω ∼ −5 Ω  radiation (relic and ) R 10 << m

→ Ω ≈  matter m 0.2-0.3

→ Ω ≅ −2 . visible (baryonic) matter b 0.02 h . dark matter (CDM, WDM, some HDM) → Ω Ω − Ω DM = m b → Ω − Ω dark energy (cosmological constant or quintessence) Λ = 1 m

Every dark matter candidate has a typical signature in the Universe. The Universe itself is a giant laboratory for testing new physics.

HLPW 2008 WhatWhat isis mirrormirror mattermatter ??

Idea: there can exist a hidden mirror sector of particles and interactions which is the exact duplicate of our observable world. (Lee and Yang, 1956; Foot,Lew,Volkas,1991)

Theory: product G×G′ of two sectors with the identical particle contents. Two sectors communicate via gravity. A symmetry P(G→G′), called mirror parity, implies that both sectors are described by the same Lagrangians.

GSM = SU(3) × SU(2) × U(1) → standard model of observable particles

G′SM = [SU(3) × SU(2) × U(1)]′ → mirror counterpart with analogous particles

Mirror photons cannot interact with ordinary baryons ⇒ dark matter !

Until now mirror particles can exist without violating any known experiment   we need to compare their astrophysical consequences with observations.

Their microphysics is the same but… cosmology is not the same !!

HLPW 2008 MirrorMirror baryonsbaryons asas darkdark mattermatter

TOT=mr≈1 2 mirror parameters  =  ' = 1 m b b CDM b CDM T ' b ' x= = T b 2 −5 4 r h =4.2⋅10 1x 

HLPW 2008 MirrorMirror baryonsbaryons asas darkdark mattermatter

TOT=mr≈1 2 mirror parameters  =  ' = 1 m b b CDM b CDM T ' b ' x= = T b 2 −5 4 r h =4.2⋅10 1x 

BBNBBN boundsbounds If particles in the two sectors O and M had the same cosmological densities ⇒ ⇒ conflict with BBN (T ~ 1MeV)!!

If T′=T , mirror photons, electrons and neutrinos → ∆Nν ≈ 6.14

Bound on the effective number of extra neutrinos: ∆Nν < 1 ⇒ T′/T < 0.64 ⇓ Due to the temperature difference, in the M sector all key epochs proceed at somewhat different conditions than in the O sector!

HLPW 2008 ThermodynamicsThermodynamics

2 2  4  4 t= gT T ≠' t = g'T 'T ' g'≠g 30 30 T ' t ≠T t ⇒ 2 2 2 2 st= qT T 3 t≠s 't = q' T 'T '3t q '≠q 45 45

During the Universe expansion, the 1/3 s' two sectors evolve with separately x≡ is time independent conserved entropies.  s 

T 't  qT  1/ 3 =x T t [ q' T ' ] T ' x= free parameter ! ⇒ T x q 'T '≈qT 

1 T 2 T ' 2 H t = =1.66  gT  =1.66  g'T ' 2t M Pl M Pl gT ≈gT 1x4 g' T ≈g' T '1x−4 

HLPW 2008 ThermodynamicsThermodynamics

During the Universe expansion, the 1/3 s' two sectors evolve with separately x≡ is time independent conserved entropies.  s 

T 't  qT  1/ 3 =x T t [ q' T ' ] T ' x= free parameter ! ⇒ T x q 'T '≈qT 

1 T 2 T ' 2 H t = =1.66  gT  =1.66  g'T ' 2t M Pl M Pl gT ≈gT 1x4 g' T ≈g' T '1x−4  the contribution of the mirror species is negligible in view of the BBN constraint!

HLPW 2008 DegreesDegrees ofof freedomfreedom inin aa MirrorMirror UniverseUniverse

3 22 7/8 qeT 'q  T ' = 21 7/8q  T  '  3 22 7/8 qeT q T = 21 7/8 q  T  

3 3 3 3 s'⋅a [ 7/8 qe T 'q ] T ' 7/8q T  ' x = 3 = 3 3 s⋅a [ 7/8qe T q ] T 7/8 qT 

e+-e- annihilation epoch changes according with x

HLPW 2008 4 g−ge T −g T N = ⋅ 7/8⋅2  T  

standard model: N eff =3.046 Mangano et al. (astro-ph/0612150)  eff 1.4 show some tension between degrees BBN: N  =3.1−1.2 of freedom at different epochs. eff 1.6 CMB+LSS+Ly+BAO: N  =4.6−1.5

Mirror matter naturally predicts different degrees of freedom at BBN (1 MeV) and recombination (1 eV) epochs!

HLPW 2008 BigBig BangBang nucleosynthesisnucleosynthesis

2 fundamental parameters: −3 degrees of freedom (extra- families), baryon to photon ratio: '= x 

HLPW 2008 BigBig BangBang nucleosynthesisnucleosynthesis

2 fundamental parameters: −3 degrees of freedom (extra- families), baryon to photon ratio: '= x 

Mirror sector is a He-world!

HLPW 2008 StructureStructure formationformation

2 Matter-radiation equality (MRE) epoch m 4 m h 1zeq= ≈2.4⋅10 4 r 1x 1 1z = 1z  eq 1x4 eq

T Baryon-photon decoupling dec T dec≈0.26 eV ⇒ 1zdec= ≈1100 (MRD) epoch T 0 −1 3 −1 T ' dec≈T dec ⇒ 1z ' dec≈x 1zdec≈1.1⋅10 x

The MRD in the M sector occurs earlier than in the O one!

2 −1 xxeq≈0.046m h 

For small x the M matter decouples before the MRE moment → it manifests as the CDM as far as the LSS is concerned (but there still can be a crucial difference at smaller scales which already went non-linear).

HLPW 2008 TheThe JeansJeans massmass

3  4 J ' J '=v S ' M J '= b ' G  3  2   dom

4 3/2 14 −1/2 −3/2 x 2 −2 M ' a '=3.2⋅10 M ⊙  1  h  J dec  1x4  b 4 3/2 −1/2 x M ' a '≈ M a  J dec  1x4  J dec x=0.6  ≈ ≈ 14 =2 M J ' 0.03 M J 10 M⊙

M J ' max xeq /2≈0.005MJ 'max  xeq

M J ' max 2 xeq≈64 M J 'max x eq

HLPW 2008 TheThe JeansJeans massmass

3  4 J ' J '=v S ' M J '= b ' G  3  2   dom

M J ' max xeq /2≈0.005MJ 'max  xeq

M J ' max 2 xeq≈64 M J 'max x eq

HLPW 2008 TheThe JeansJeans massmass

3  4 J ' J '=v S ' M J '= b ' G  3  2   dom

M J ' max xeq /2≈0.005MJ 'max  xeq

M J ' max 2 xeq≈64 M J 'max x eq

HLPW 2008 Dissipative effects The M baryons density fluctuations should undergo the strong collisional damping around the time of M recombination due to photon diffusion, which washes out the perturbations at scales smaller than the M Silk scale MS'.

12 2 −5/ 4 M S≈6.2⋅10 b h  M⊙

2 14 b h =0.02 ⇒ M S≈8⋅10 M ⊙

3 2 −5/ 4 12 M S '≈[ f x/2] b ' h  ⋅10 M ⊙ 5/ 4 f  x=x xxeq 3/2 5/ 4 f  x=x / xeq xeq xxeq

7 2 −5 10 M S ' xeq ≈10 b h  M⊙≈3⋅10 M⊙

Differences with the WDM free streaming damping: • the M baryons should show acustic oscillations in the LSS power spectrum; • such oscillations, transmitted via gravity to the O baryons, could cause observable anomalies in the CMB power spectrum.

HLPW 2008 Scenarios

xxeq  adec 'adec xxeq  adec 'adec

M pert M J ' aeq  growth M pert M J ' adec '  growth M S 'M pertM J 'aeq   grow.oscill.grow. M pert M S '  dissipation M pert M S '  dissipation

HLPW 2008 Temporal evolution of perturbations Ω Ω ω x dependence ( 0 = 1, m = 0.3, b = 0.02, h = 0.7 ; λ ≈ 60 Mpc)

HLPW 2008 CosmicCosmic MicrowaveMicrowave BackgroundBackground

T −5 T=2.725±0.001 K ≈10 T T  , ∞ l =∑ ∑ alm Y lm , T l=0 m=−l

l 2 1 2 2 Cl =al ≡ ∑ ∣alm∣ =〈∣alm∣ 〉 2l1 m=−l

2 T l ≡ll1Cl /2

HLPW 2008 MirrorMirror CMBCMB

We start from a reference model

tot =1

m=0.30

CDM =m−b ' 2 b h =0.02 h=0.70

ns=1.00

and we replace CDM…

x=0.3 ,0.5 ,0.7

b '=nbn=1,2,3,4,...

HLPW 2008 MirrorMirror CMBCMB

We start from a reference model

tot =1

m=0.30

CDM =m−b ' 2 b h =0.02 h=0.70

ns=1.00

and we replace CDM…

x=0.3 ,0.5 ,0.7

b '=nbn=1,2,3,4,...

• low x → CDM Ω ′ • small dependence on b

HLPW 2008 LargeLarge ScaleScale StructureStructure

Field of density perturbations:

x−0 1 −i k⋅x 3 x≡ x= 3 ∫k e d k 0 2

The power spectrum:

2 n Pk≡〈∣k∣ 〉=A k

The transfer function: T(k) 2 Dt f  2 Pk ;t f = T k ;t f  Pk ;ti  [ Dti  ]

HLPW 2008 MirrorMirror LSSLSS

At linear scales…

• low x → CDM

• high dependence on x Ω ′ • high dependence on b

Ω ′ → • higher b deeper oscillations

HLPW 2008 ComparisonComparison withwith observationsobservations

→ Ω ′ • for high x high b excluded → Ω ′ • for low x every b permitted

HLPW 2008 MirrorMirror darkdark starsstars (evolution) microlensing ⇒⇒ Massive Astrophysical Compact events Halo Objects (MACHOs)

7.5 5.5 L∝ M X t ∝ 4 7.5 MS 1.4 T e ∝

faster evolutionary times!

HLPW 2008 MirrorMirror summarysummary OBSERVATIONS THEORY

HLPW 2008 MirrorMirror summarysummary

Thermodynamics of the early Universe OBSERVATIONS THEORY

HLPW 2008 MirrorMirror summarysummary

Thermodynamics of the early Universe

Big Bang

Nucleosynthesis OBSERVATIONS THEORY

HLPW 2008 MirrorMirror summarysummary

Primordial nuclear Thermodynamics of abundances the early Universe

Big Bang

Nucleosynthesis OBSERVATIONS

Star formation

THEORY Star evolution

HLPW 2008 MirrorMirror summarysummary

Primordial nuclear Thermodynamics of abundances the early Universe

Big Bang

Nucleosynthesis OBSERVATIONS

Star formation

THEORY Star evolution

MACHOs population

Gravitational waves

HLPW 2008 MirrorMirror summarysummary

Primordial nuclear Thermodynamics of abundances the early Universe

Big Bang

Nucleosynthesis OBSERVATIONS

Star formation

THEORY Star evolution

MACHOs population

N-body Gravitational simulations waves

Galaxy formation and evolution

HLPW 2008 MirrorMirror summarysummary

Primordial nuclear Thermodynamics of abundances the early Universe

Big Bang CMB and LSS power spectra Nucleosynthesis OBSERVATIONS

Gravitational lensing Star formation

THEORY Star evolution

MACHOs population Structure formation N-body Gravitational simulations waves

Galaxy formation and evolution

HLPW 2008 MirrorMirror summarysummary

Primordial nuclear Thermodynamics of abundances the early Universe

Big Bang CMB and LSS power spectra Nucleosynthesis OBSERVATIONS

Gravitational lensing Star formation Galactic DM distribution THEORY Star evolution

MACHOs population Structure formation N-body Gravitational simulations waves

Galaxy formation Strange events: and evolution dark galaxies, bullet galaxies, ...

HLPW 2008 MirrorMirror summarysummary

Primordial nuclear Thermodynamics of abundances the early Universe

Big Bang CMB and LSS power spectra Nucleosynthesi OBSERVATIONS s Gravitational lensing Star formation Galactic DM distribution THEORY Star evolution

MACHOs population Structure formation N-body Gravitational simulations waves

Galaxy formation Strange events: and evolution dark galaxies, bullet galaxies, ...

HLPW 2008 MirrorMirror summarysummary

Primordial nuclear Thermodynamics of abundances the early Universe

Big Bang CMB and LSS power spectra Nucleosynthesi OBSERVATIONS s Gravitational lensing Star formation Galactic DM distribution THEORY Star evolution

MACHOs population Structure formation N-body Gravitational simulations waves

Galaxy formation Strange events: and evolution dark galaxies, bullet galaxies, ...

HLPW 2008