Cosmology Falling in Love with Sterile Neutrinos Jörn Kersten Based on Torsten Bringmann, Jasper Hasenkamp, JK, JCAP 07 (2014) [arXiv:1312.4947] Outline 1 Introduction 2 Self-Interacting Dark Matter 3 Dark Matter Interacting with Neutrinos 3 / 23 1 Introduction 2 Self-Interacting Dark Matter 3 Dark Matter Interacting with Neutrinos 4 / 23 Or does it? Tensions in ΛCDM cosmology The Universe after Planck Flat ΛCDM cosmology fits data perfectly Planck, arXiv:1303.5062 5 / 23 The Universe after Planck Flat ΛCDM cosmology fits data perfectly Planck, arXiv:1303.5062 Or does it? Tensions in ΛCDM cosmology 5 / 23 Measurements of Cosmic Microwave Background (CMB): ∆Neff = 1:51 ± 0:75 at 68% CL ACT, ApJ 739 (2011) ∆Neff = 0:81 ± 0:42 at 68% CL SPT, ApJ 743 (2011) +0:68 ∆Neff = 0:31−0:64 at 95% CL Planck, arXiv:1303.5076 Hints for Dark Radiation Dark radiation: relativistic particles 6= γ; νSM Parameterized via radiation energy density " # 7 T 4 ρ ≡ 1 + N ν ρ rad eff 8 T γ T ≡ Tγ Neff: effective number of neutrino species Standard Model: Neff = 3:046 Existence of dark radiation , ∆Neff ≡ Neff − 3:046 > 0 6 / 23 Hints for Dark Radiation Dark radiation: relativistic particles 6= γ; νSM Parameterized via radiation energy density " # 7 T 4 ρ ≡ 1 + N ν ρ rad eff 8 T γ T ≡ Tγ Neff: effective number of neutrino species Standard Model: Neff = 3:046 Existence of dark radiation , ∆Neff ≡ Neff − 3:046 > 0 Measurements of Cosmic Microwave Background (CMB): ∆Neff = 1:51 ± 0:75 at 68% CL ACT, ApJ 739 (2011) ∆Neff = 0:81 ± 0:42 at 68% CL SPT, ApJ 743 (2011) +0:68 ∆Neff = 0:31−0:64 at 95% CL Planck, arXiv:1303.5076 6 / 23 Measurements 7 CDM+Neff+k+f+ns CDM+Neff+k+f+w CDM+Neff+f+w CDM+Neff+k+f CDM+Neff+k CDM+Neff+Yp CDM+Neff+f CDM+Neff 6 5 eff N 4 3 2 W7+SPT+BAO+H0+Union2W7+CMB+LRG+SN+H0W7+CMB+BAO+SN+H0W7+CMB+LRG+H0W7+CMB+BAO+H0W7+H0+WL+BAO+H(z)+Union2W7+SPT+WiggleZ+H(z)+BAO+SNLSW9+SPT+WiggleZ+H(z)+BAO+SNLSW7+SPT+BAO+H0W7+SPT+BAO+H0+Union2W7+ACT+SPT+BAO+H0W7+ACT+SPT+BAO+H0W7+BAO+H0W7+ACTW7+ACT+BAO+H0W7+SPT+WiggleZ+H(z)+BAO+SNLSW7+CMB+LRG+H0W7+CMB+BAO+H0W7+ACT+SPT+LRG+H0W7+SPTSZ+BAO+H0W7+SDSS+H0W7+SDSS+H0+Union2W7+SDSS+H0+Union2+W7+H0+WL+BAO+H(z)+Union2W7+SPT+BAO+H0W7+SNLS+BAO+BOSSW7+SPT+BAO+H0W9+STP+H0W9+STP+H0+BAOW9+ACT+H0W9+ACT+H0+BAOPl+WP+SPT+ACT+BAO4 D/H D/H+ W7+D/HW7+SPT(agnostic)W7+SPTW7+ACT+SPT+BAO+H0W7+ACT+SPT+LRG+H0W7+SPT+BAO+H0W7+SPTW7+ACT+BAO+H0W7+ACTW7+LRG+H0W7+BAO+H0W5+LRG+maxBGC+H0W5+CMB+BAO+fgas+H0W5+LRG+H0W5+BAO+SN+H0W7+H0+SDSS+SN+CHFTLSW7+SPT+H(z)+H0W7+H0+WL+BAO+H(z)+Union2W7+ACBAR+BAO+H0+ACTW7+ACBAR+ACT+SPT+SDSS+H0W7+ACBAR+ACT+SPT+SDSS+MSH0W7+SPT+BAO+H0W7+SPTW7+H0W7+SPT+BAO+H0W7+SPTW7+SPT+BAO+H0W9+ACT+SPT+BAO+H0W9+ACTW9+SPTW9+ACT+SPTW9+ACT+SPT+lensingPl+WP Pl+WP+SPT+ACT+BAO He 33 34 4 He 68 59 36 35 14 38 42 44 58 61 64 65 28 30 13 45 46 49 21 66 50 37 52 9 15 25 27 29 31 41 43 57 60 62 4 5 17 18 20 22 67 47 2 26 3 32 69 4 11 12 19 39 40 63 He+D/H 48 1 10 54 51 6 24 53 23 55 7 8 16 56 Modified from Riemer-Sørensen et al. (2013 review) arXiv:1301.7102 arXiv:1301.7102 etal. (2013 review) Modified from Riemer-Sørensen Resolved by hot dark matter component ' dark radiation Best fit: ∆Neff = 0:61 3 meff ≡ Ts m = 0:41 eV s Tν s Hamann, Hasenkamp, JCAP 10 (2013) Wyman, Rudd, Vanderveld, Hu, PRL 112 (2014) Battye, Moss, PRL 112 (2014) Gariazzo, Giunti, Laveder, JHEP 11 (2013) Hints for Hot Dark Matter 2 ::: 3 σ tension: CMB (z > 1000) vs. local (z < 10) observations Expansion rate km Planck: H0 = (67:3 ± 1:2) s Mpc arXiv:1303.5076 km Hubble: H0 = (73:8 ± 2:4) s Mpc Riess et al., ApJ 730 (2011) Magnitude of matter density fluctuations( σ8) 8 / 23 Hints for Hot Dark Matter 2 ::: 3 σ tension: CMB (z > 1000) vs. local (z < 10) observations Expansion rate km Planck: H0 = (67:3 ± 1:2) s Mpc arXiv:1303.5076 km Hubble: H0 = (73:8 ± 2:4) s Mpc Riess et al., ApJ 730 (2011) Magnitude of matter density fluctuations( σ8) Resolved by hot dark matter component ' dark radiation Best fit: ∆Neff = 0:61 3 meff ≡ Ts m = 0:41 eV s Tν s Hamann, Hasenkamp, JCAP 10 (2013) Wyman, Rudd, Vanderveld, Hu, PRL 112 (2014) Battye, Moss, PRL 112 (2014) Gariazzo, Giunti, Laveder, JHEP 11 (2013) 8 / 23 on large scales Astrophysics solutions or new particle physics? Small-Scale Problems of Structure Formation Numerical simulations of structure formation with cold dark matter Springel, Frenk, White, Nature 440 (2006) Excellent agreement with observations 9 / 23 Astrophysics solutions or new particle physics? Small-Scale Problems of Structure Formation Numerical simulations of structure formation with cold dark matter Springel, Frenk, White, Nature 440 (2006) Excellent agreement with observations on large scales 9 / 23 Astrophysics solutions or new particle physics? Small-Scale Problems of Structure Formation Missing satellites Cusp-core Too big to fail Kravtsov, Adv. Astron. (2010) De Blok et al., ApJ 552 (2001) Boylan-Kolchin et al., Klypin et al., ApJ 522 (1999) MNRAS 422 (2011) More cuspy density More galactic Most massive profiles predicted satellites predicted satellites predicted than observed than observed denser than observed 9 / 23 Small-Scale Problems of Structure Formation Missing satellites Cusp-core Too big to fail Kravtsov, Adv. Astron. (2010) De Blok et al., ApJ 552 (2001) Boylan-Kolchin et al., Klypin et al., ApJ 522 (1999) MNRAS 422 (2011) More cuspy density More galactic Most massive profiles predicted satellites predicted satellites predicted than observed than observed denser than observed Astrophysics solutions or new particle physics? 9 / 23 1 Introduction 2 Self-Interacting Dark Matter 3 Dark Matter Interacting with Neutrinos 10 / 23 Not-so-WIMPy Dark Matter Dark matter χ Standard Model singlet Charged under U(1)X gauge interaction Mass mχ ∼ TeV V ν χ χ χ χ Light gaugeχ boson V , mV ∼ MeV... ν¯ Long-range, velocity-dependentV ... interactionν V ... V Less cuspy density profiles ... χ¯ χ¯ χ¯ ν ν Cusp-core and too big to fail solvedV ν¯ Feng, Kaplinghat, Yu, PRL 104 (2010) Loeb, Weiner, PRL 106 (2011) Vogelsberger, Zavala, Loeb, MNRAS 423 (2012) 11 / 23 mχv TeV 10 km=s Here: ∼ 5 ∼ 30 1 mV MeV 3 · 10 km=s classical regime analytical approximations exist Velocity-Dependent Self-Interactions αX −mV r Described by Yukawa potential V (r) = ± r e Desired scattering cross section σT : Large in dwarf galaxies Small on larger scales to satisfy experimental limits Very different behavior depending on model parameters 100 D dwarf Milky Way cluster øøøø 7 only 10 øøøø 10 Classical Resonant Born øøø ø ø øø L 1 ø g 4 10 øø 2 0.1 ø cm attractive ø 10 H @ ø L -2 X g ø 10 m 2 0.01 -3 Born T cm H 10 mX=200 GeV resonant s -5 -2 X classical 10 a =10 -4 X m 10 v=10 kms T -8 s 10 10-5 10 100 1000 0.001 0.01 0.1 1 v km s mf HGeVL Tulin, Yu, Zurek, PRL 110, PRD 87 (2013) H L 12 / 23 Velocity-Dependent Self-Interactions αX −mV r Described by Yukawa potential V (r) = ± r e Desired scattering cross section σT : Large in dwarf galaxies Small on larger scales to satisfy experimental limits Very different behavior depending on model parameters 100 D dwarf Milky Way cluster øøøø 7 only 10 øøøø 10 Classical Resonant Born øøø ø ø øø L 1 ø g 4 10 øø 2 0.1 ø cm attractive ø 10 H @ ø L -2 X g ø 10 m 2 0.01 -3 Born T cm H 10 mX=200 GeV resonant s -5 -2 X classical 10 a =10 -4 X m 10 v=10 kms T -8 s 10 10-5 10 100 1000 0.001 0.01 0.1 1 v km s mf HGeVL Tulin, Yu, Zurek, PRL 110, PRD 87 (2013) H L mχv TeV 10 km=s Here: ∼ 5 ∼ 30 1 mV MeV 3 · 10 km=s classical regime analytical approximations exist 12 / 23 Simulating Self-Interacting Dark Matter Simulation: formation of dwarf galaxy with dark matter + baryons dA: SIDM10 109 DM:CDM-B stars:CDM-B DM:SIDM1-B stars:SIDM1-B DM:SIDM10-B stars:SIDM10-B DM:vdSIDMa-B stars:vdSIDMa-B DM:vdSIDMb-B stars:vdSIDMb-B ] 108 3 − c p k ¯ M [ 7 10 ρ dA 6 1 0 1 2 10 −3 200 400 600 1000 3000 log[ρ/(M ⊙kpc )] r [pc] Vogelsberger, Zavala, Simpson, Jenkins, MNRAS 444 (2014) Core, size depends on strength of self-interactions 13 / 23 1 Introduction 2 Self-Interacting Dark Matter 3 Dark Matter Interacting with Neutrinos 14 / 23 Problem: explicit breaking of SU(2)L Late Kinetic Decoupling Standard Model neutrinos coupled to V V ν χ χ χ χ χ Dark matter... scatters off neutrinos ν¯ V Tχ =...Tν until kinetic decouplingν V at T ...∼ 100 eV V Formation of..