Gravitational waves from Massive Primordial Black Holes as Dark Matter

Transcription

1 Gravitational waves from Massive Primordial Black Holes as Dark Matter based on S. Clesse & JGB, arxiv: S. Clesse & JGB, Phys Rev D92 (2015) JGB, Linde & Wands, Phys Rev D54 (1996) 6040 Juan García-Bellido 8 th September 2016

2 Outline Discovery of 3 binary BH by aligo starts a new era of GW Astronomy Massive PBH could be the main component of Dark Matter Specific signatures of PBH Future: Testing the idea with cosmological observations Conclusions

3

4

5 aligo Collab. (2016)

6 aligo Collab. (2016) Very massive!

7 probability black hole merger

8 Gravitational Wave Astronomy Discovery of binary BH by aligo VIRGO, KAGRA, INDIGO = GW Astron GW = M sun BH binary GW = M sun BH binary LVT = M sun candidate Expected events/yr/gpc 3 aligo+ can map the mass and spin of Massive BH (10 M sun < M BH < 150 M sun )

9 Massive Primordial Black Holes as DM

10

11 Steven Weinberg our problem is not that we take our theories too seriously, but that we don't take them seriously enough

12

13

14 V (φ) Potential inflection point φ

15 logp(k) Power spectrum 10 1 GBLW ('96) CGB('15) 10 5 ΛCDM CMB reion LSS logk

16 logp(k) Power spectrum clustering & merging 10 5 logk

17 Mass formation during radiation era Clesse, JGB (2015)

18 Mass MR equality Clesse, JGB (2015)

19 Constraints on Primordial Black Holes

20 Present Constraints on PBH Clesse, JGB (2015)

21 Massive Primordial Black Holes These are NOT the (small) PBH with M < M PBH <10-6 M of Carr et al. These are MASSIVE black holes with 10-2 M < M PBH <10 5 M which cluster and merge and could resolve some of the most acute problems of ΛCDM paradigm. ΛCDM N-body simulations never reach the 100 M particle resolution, so for them PBH is as good as PDM.

22 logn Mass distribution of BH SBH PBH IMBH SMBH 1M 50M 10 3 M 10 9 M Θ Θ Θ Θ log M

23 Mass-σ relation BH at G.C. MacConnel & Ma (2013) SMBH IMBH Kruijssen et al. (2013)

24 Distinguish MPBH from Stellar BH Accretion disks Distribution of spins Mass distribution IMF SBH kicks at formation vs static PBH Galaxy formation rate gal. seeds Microlensing events of long duration GAIA anomalous astrometry CMB distortions with PIXIE/PRISM Reionization faster in the past N-body simulations below 10 2 M sun

25 Signatures of Primordial Black Holes

26 Microlensing

27 symmetric achromatic unique

28 A = 2 + u2 u 4 + u 2 u = r r E amplification Δt = r E υ = 4GM Dd υ average 1 2 crossing M D = 10 M Θ Δt = 1.23 years M D = 1 M Θ Δt = 5 months M D = 0.1 M Θ Δt = 1.5 months M D = 10 2 M Θ Δt = 2 weeks M D = 10 4 M Θ Δt = 1.5 day

29 P. Tisserand (2007)

30 Astrometric GAIA

31 GAIA position + velocity anomalies Thomson model PDM

32 GAIA position + velocity anomalies Rutherford model PBH

33 Average distance between PBH M halo MW (< 50kpc) = M Θ λ (n ) 1/ 3 M = 20 pc BH BH 50M Θ 1/ 3 20 pc stars per black hole of 50 M Θ in our (solar) neighbourhood

34 Anomalous accelerations The acceleration on any given star is due to the surrounding masses. A uniform DM field does not induce an extra force on. The only feels the presence of other s a i = GM BH b 2 + j Gm j r ij 2 u ˆ ij Δa = GM BH b 2 = ms 2 M 50M Θ 20pc b 2

35 Anomalous velocities & positions The relative velocity change of a due to PBH, for a 220 km/s relative motion is Δv v = M 50M Θ 0.1pc b 2 The relative displacement of a at 1 kpc Δx x = 0.56 marcsec M 50M Θ 0.1pc b 2

36 Gravitational slingshot effect Close encounters of a star with 100 km/s relative motion is enough to expel the star from the globular cluster. m v 2 v 1 U M v 2 = 2 U +(1- m/m) (1 +m/m) It may explain large M/L ratios of dsph by ejection of stars in the cluster, v>v esc. v 1

37 Fluctuations CIB & X-ray Background

38 Kashlinsky (2016)

39 Kashlinsky (2016)

40 Grav. Waves aligo

41

42 Clesse, JGB arxiv:

43 Grav. Waves elisa

44

45 Sesana (2013)

46 Stochastic Background Grav. Waves

47 Stochastic Background from MPBH aligo arxiv: h 2 Ω GW = f Hz 2 / 3 M c 100M Θ 5 / 3

48 Primordial Black Holes as Dark Matter

49 Sensitivity of future GW antenas h c ( f ) = f Hz 2 / 3

50 Discussion

51 Signatures of MPBH as DM Seeds of galaxies at high-z Reionization starts early (Kashlinsky) Larger galaxies form earlier than ΛCDM Massive BH at centers z>6 Growth of structure on small scales Ultra Luminous X-ray Transients MPBH in Andromeda (Chandra) GW from inspiraling BH (LIGO) Substructure and too-big-to-fail probl. Total integrated mass = Ω M

52 Future tests GAIA positions and velocities of stars CMB distortions with CORE+ GW from PBH mergers with LIGO Growth of structure on small scales Reionization history with SKA Direct detection from astrophysics (GAIA, X-rays and gamma-rays) SN or GRB femtolensing on MPBH Microlensing (long duration events) Stochastic Grav. Wave Background

53 Conclusions Massive Primordial Black Holes are the perfect candidates for CDM, in excellent agreement with CMB and LSS observations. MPBH could also resolve some of the most acute problems of ΛCDM paradigm, like early structure formation and substructure problems. MPBH open a new window into the Early Universe. There are many ways to test this idea in the near future from CMB, LSS, X-rays and GW. LISA could detect the stochastic background from MPBH merging since recombination.