Bounds on evolution histories of the early Universe from indirect - PowerPoint PPT Presentation

Bounds on evolution histories of the early Universe from indirect dark matter searches Riccardo Catena Istitut für Theoretische Physik (ITP), Heidelberg 22.07.10 R. C., N. Fornengo, M. Pato, L. Pieri and A. Masiero, Phys. Rev. D 81 (2010) M. Schelke, R. C., N. Fornengo, A. Masiero and M. Pietroni, Phys. Rev. D 74 (2006) R. C., N. Fornengo, A. Masiero, M. Pietroni and F. Rosati, Phys. Rev. D 70 (2004) Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 1 / 17

Overview - Can the early Universe expand faster than in General Relativity? - If yes, thermal dark matter has larger annihilation cross section : H f Ω DM h 2 ∝ = ⇒ “Cosmological boost factor” � σ ann v � f - In Scalar-Tensor theories it is possibile to realize H / H GR >> 1 . C., N. Fornengo, A. Masiero, M. Pietroni and F. Rosati, Phys. Rev. D 70 (2004) 1000 100 2 H JF 2 H GR �������� 10 1 -17.5 -15 -12.5 -10 -7.5 -5 -2.5 0 � log 10 � T T 0 � ������� Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 2 / 17

Overview: theories with H � = H GR T 4 1 H 2 ρ tot ≃ 2 . 76 g ∗ GR = 3 M 2 M 2 p p Change the number of relativistic d.o.f.’s, g ∗ ; 1 Consider a ρ tot not dominated by relativistic d.o.f.’s; 2 - Kination . Salati, Phys. Lett. B 571 (2003) 121 P 3 Consider theories where the effective Planck mass is different from the constant M p : - Scalar-Tensor theories R. C., N. Fornengo, A. Masiero, M. Pietroni and F. Rosati, Phys. Rev. D 70 (2004) 063519 - Extradimensions L. Randall and R. Sundrum, Phys. Rev. Lett. 83 (1999) 4690 - . . . Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 3 / 17

Overview -Can we set an upper bound for such cosmological boosts? Yes - Main assumption: Thermal dark matter production - Method: The Boltzmann equation n + 3 Hn = −� σ ann v � ( n 2 − n 2 ˙ eq ) H f Ω DM h 2 ∝ � σ ann v � f Ω DM h 2 = 9 ⇒ from WMAP > > = Constraints on H f = ⇒ � σ ann v � f = ⇒ bounds from indirect > > dark matter detection ; Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 4 / 17

Outline 1 The dark matter decoupling Bounds on � σ ann v � f from indirect dark matter searches 2 3 Bounds on the Hubble expansion 4 Conclusions Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 5 / 17

Outline 1 The dark matter decoupling Bounds on � σ ann v � f from indirect dark matter searches 2 3 Bounds on the Hubble expansion 4 Conclusions Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 5 / 17

Outline 1 The dark matter decoupling Bounds on � σ ann v � f from indirect dark matter searches 2 3 Bounds on the Hubble expansion 4 Conclusions Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 5 / 17

Outline 1 The dark matter decoupling Bounds on � σ ann v � f from indirect dark matter searches 2 3 Bounds on the Hubble expansion 4 Conclusions Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 5 / 17

The dark matter decoupling - The Boltzmann equation: n + 3 Hn = −� σ ann v � ( n 2 − n 2 ˙ eq ) - Two rates: 1) Hubble rate H 2) Annihilation rate Γ = n � σ ann v � - When H / Γ > 1 = ⇒ dark matter decoupling Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 6 / 17

The dark matter decoupling: a window on the early Universe - From the Boltzmann equation: H f Ω DM h 2 ∝ � σ ann v � f - The ratio H f / � σ ann v � f is fixed by CMB observations ⇒ A bound on � σ ann v � f can constrain H f = Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 7 / 17

Bounds on � σ ann v � from indirect dark matter searches: data Charged particles: -Antiprotons (PAMELA) -Positron fraction (PAMELA) -Electron+positron flux (FERMI,HESS) γ -rays: -Diffuse emission (Fermi,EGRET) -From the galactic center (HESS) Radio photons: -Radio observations from the galactic center R.D.Davies, D.Walsh, R.S.Booth, MNRAS 177, 319-333 (1976) Optical depth of CMB photons (WMAP) Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 8 / 17

Bounds on � σ ann v � from indirect dark matter searches: assumptions -s-wave annihiations -Dark matter profile: 1) Via Lactea II simulation 2) Aquarius simulation 3) Cored profile with ρ local ≃ 0 . 4 GeV cm − 3 R. Catena and P . Ullio, arXiv:0907.0018 [astro-ph.CO]. To be published in JCAP -Diffusion model: . Salati, Phys. Rev. D 69 (2004) 063501 F. Donato, N. Fornengo, D. Maurin and P J. Lavalle, Q. Yuan, D. Maurin and X. J. Bi, arXiv:0709.3634 [astro-ph] -Annihilation channels: DM+DM → e + + e − , τ + + τ − , µ + + µ − , W + + W − , b + ¯ b Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 9 / 17

Bounds on � σ ann v � from indirect dark matter searches: DM+DM → e + + e − 1. � 10 � 20 1. � 10 � 20 unitarity bound 1. � 10 � 21 1. � 10 � 21 ICS Γ from GC 1. � 10 � 22 1. � 10 � 22 EGRET 10 � 20 FERMI 10 � 20 EGRET 5x30 �Σ ann v � � cm 3 s � 1 � EGRET 10x60 1. � 10 � 23 1. � 10 � 23 1. � 10 � 24 1. � 10 � 24 optical depth e � e � � e � 1. � 10 � 25 1. � 10 � 25 e � � e � 1. � 10 � 26 1. � 10 � 26 e � radio band e � � e � best � fit VL2 DM � DM � e � � e � 1. � 10 � 27 1. � 10 � 27 MED propagation Γ e � 3.3 1. � 10 � 28 1. � 10 � 28 10 100 1000 50 500 5000 1 � 10 4 m DM � GeV � Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 10 / 17

Bounds on � σ ann v � from indirect dark matter searches: DM+DM → e + + e − 1. � 10 � 20 1. � 10 � 20 1. � 10 � 20 1. � 10 � 20 unitarity bound unitarity bound 1. � 10 � 21 1. � 10 � 21 1. � 10 � 21 1. � 10 � 21 ICS ICS Γ from GC EGRET 10 � 20 Γ from GC 1. � 10 � 22 1. � 10 � 22 1. � 10 � 22 1. � 10 � 22 FERMI 10 � 20 EGRET 10 � 20 EGRET 5x30 FERMI 10 � 20 EGRET 10x60 EGRET 5x30 �Σ ann v � � cm 3 s � 1 � �Σ ann v � � cm 3 s � 1 � EGRET 10x60 1. � 10 � 23 1. � 10 � 23 1. � 10 � 23 1. � 10 � 23 1. � 10 � 24 1. � 10 � 24 1. � 10 � 24 1. � 10 � 24 e � � e � optical depth e � e � � e � e � 1. � 10 � 25 1. � 10 � 25 1. � 10 � 25 1. � 10 � 25 e � � e � optical depth e � � e � radio band 1. � 10 � 26 1. � 10 � 26 1. � 10 � 26 1. � 10 � 26 e � radio band e � e � � e � best � fit VL2 AQU e � � e � best � fit DM � DM � e � � e � DM � DM � e � � e � 1. � 10 � 27 1. � 10 � 27 1. � 10 � 27 1. � 10 � 27 MED propagation MED propagation Γ e � 3.3 Γ e � 3.3 1. � 10 � 28 1. � 10 � 28 1. � 10 � 28 1. � 10 � 28 10 50 100 500 1000 5000 1 � 10 4 10 50 100 500 1000 5000 1 � 10 4 m DM � GeV � m DM � GeV � 1. � 10 � 20 1. � 10 � 20 Γ from GC unitarity bound 1. � 10 � 21 1. � 10 � 21 e � radio band e � � e � 1. � 10 � 22 1. � 10 � 22 �Σ ann v � � cm 3 s � 1 � 1. � 10 � 23 1. � 10 � 23 ICS 1. � 10 � 24 1. � 10 � 24 EGRET 5x30 e � � e � EGRET 10 � 20 FERMI 10 � 20 1. � 10 � 25 optical depth EGRET 10x60 1. � 10 � 25 e � 1. � 10 � 26 1. � 10 � 26 e � � e � best � fit ISO DM � DM � e � � e � 1. � 10 � 27 1. � 10 � 27 MED propagation Γ e � 3.3 1. � 10 � 28 1. � 10 � 28 10 50 100 500 1000 5000 1 � 10 4 m DM � GeV � Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 11 / 17

Bounds on � σ ann v � from indirect dark matter searches: DM+DM → W + + W − 1. � 10 � 20 1. � 10 � 20 unitarity bound ICS Γ from GC 1. � 10 � 21 1. � 10 � 21 EGRET 10 � 20 FERMI 10 � 20 EGRET 5x30 EGRET 10x60 1. � 10 � 22 1. � 10 � 22 �Σ ann v � � cm 3 s � 1 � 1. � 10 � 23 1. � 10 � 23 e � � e � optical depth 1. � 10 � 24 1. � 10 � 24 e � e � � e � 1. � 10 � 25 1. � 10 � 25 e � e � � e � best � fit antiprotons radio band 1. � 10 � 26 1. � 10 � 26 VL2 DM � DM � W � � W � 1. � 10 � 27 1. � 10 � 27 MED propagation Γ e � 3.3 1. � 10 � 28 1. � 10 � 28 10 100 1000 50 500 5000 1 � 10 4 m DM � GeV � Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 12 / 17

Bounds on � σ ann v � from indirect dark matter searches: DM+DM → All 1. � 10 � 20 1. � 10 � 20 unitarity bound 1. � 10 � 21 1. � 10 � 21 1. � 10 � 22 1. � 10 � 22 Μ � Μ � �Σ ann v � � cm 3 s � 1 � 1. � 10 � 23 1. � 10 � 23 1. � 10 � 24 1. � 10 � 24 1. � 10 � 25 1. � 10 � 25 W � W � 1. � 10 � 26 1. � 10 � 26 Τ � Τ � b b VL2 1. � 10 � 27 1. � 10 � 27 MED propagation e � e � Γ e � 3.3 1. � 10 � 28 1. � 10 � 28 10 100 1000 50 500 5000 1 � 10 4 m DM � GeV � Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 13 / 17

Bounds on H from indirect dark matter searches - A naive bound comes from: H f Ω DM h 2 ∝ � σ ann v � f - The correct calculation (Boltzmann equation): n + 3 Hn = −� σ ann v � ( n 2 − n 2 ˙ eq ) where H is a function of the temperature - In the following: - Parametric approach „ T H 2 „ T − T re « ν « = 1 + η tanh H 2 T f T re GR Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 14 / 17

Bounds on H : Parametric approach Riccardo Catena (ITP) Paris (TeVPA 2010 22/07/2010) 15 / 17