Gravitational waves from Massive Primordial Black Holes as Dark Matter

Gravitational waves from Massive Primordial Black Holes as Dark Matter based on S. Clesse & JGB, arxiv:1603.05234 S. Clesse & JGB, Phys Rev D92 (2015) 023524 JGB, Linde & Wands, Phys Rev D54 (1996) 6040 Juan García-Bellido 8 th September 2016

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

aligo Collab. (2016)

aligo Collab. (2016) Very massive!

probability black hole merger

Gravitational Wave Astronomy Discovery of binary BH by aligo VIRGO, KAGRA, INDIGO = GW Astron GW150914 = 36 + 29 M sun BH binary GW151226 = 14 + 8 M sun BH binary LVT151012 = 23 + 13 M sun candidate Expected 50-100 events/yr/gpc 3 aligo+ can map the mass and spin of Massive BH (10 M sun < M BH < 150 M sun )

Massive Primordial Black Holes as DM

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

V (φ) Potential inflection point φ

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

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

Mass Spectrum @ formation during radiation era Clesse, JGB (2015)

Mass Spectrum @ MR equality Clesse, JGB (2015)

Constraints on Primordial Black Holes

Present Constraints on PBH Clesse, JGB (2015)

Massive Primordial Black Holes These are NOT the (small) PBH with 10-24 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.

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

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

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

Signatures of Primordial Black Holes

Microlensing

symmetric achromatic unique

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

P. Tisserand (2007)

Astrometric Anomalies @ GAIA

GAIA position + velocity anomalies Thomson model PDM

GAIA position + velocity anomalies Rutherford model PBH

Average distance between PBH M halo MW (< 50kpc) = 5.4 10 11 M Θ λ (n ) 1/ 3 M = 20 pc BH BH 50M Θ 1/ 3 20 pc 55000 stars per black hole of 50 M Θ in our (solar) neighbourhood

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 = 1 10 15 ms 2 M 50M Θ 20pc b 2

Anomalous velocities & positions The relative velocity change of a due to PBH, for a 220 km/s relative motion is Δv v = 3 10 4 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

Gravitational slingshot effect Close encounters of a star with MPBH @ 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

Fluctuations CIB & X-ray Background

Kashlinsky (2016)

Kashlinsky (2016)

Grav. Waves detections @ aligo

Clesse, JGB arxiv:1603.05234

Grav. Waves detections @ elisa

Sesana (2013)

Stochastic Background Grav. Waves

Stochastic Background from MPBH aligo arxiv:1602.03847 h 2 Ω GW = 2.2 10 9 f Hz 2 / 3 M c 100M Θ 5 / 3

Primordial Black Holes as Dark Matter

Sensitivity of future GW antenas h c ( f ) = 1.36 10 23 f Hz 2 / 3

Discussion

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 QSO @ 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

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

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.