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Scalar field dark matter and evolution of galaxies 2) Dark energy from cosmic Hawking radiation

Scalar field dark matter and evolution of galaxies 2) Dark energy from cosmic Hawking radiation. Outline. Dark Matter is in BEC or coherent Scalar field (1992) Dark energy comes from quantum entanglement or cosmic Hawking radiation . (2007).

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Scalar field dark matter and evolution of galaxies 2) Dark energy from cosmic Hawking radiation

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  1. Scalar field dark matter and evolution of galaxies • 2) Dark energy from cosmic Hawking radiation

  2. Outline • Dark Matter is in • BEC or coherent Scalar field (1992) • Dark energy comes from quantum entanglement • or cosmic Hawking radiation. (2007)

  3. Problems of CDM model • CDM model is very successful at the scale larger than galaxies. • But • Missing satellite galaxy problem • Cusp problem (rotation curve) • Angular momentum catastrophe Ostriker and Steinhardt Science 300, 20 (2003) => Min. Length scale! Solution: 1) DM playing a role of CDM at the scale larger than galaxies, and at the same time 2) suppressing sub-galactic structures. BEC/SFDM BEC/SFDM

  4. Dark matter candidates BEC/Scalar field, Repulsive, Fluid

  5. Evolution tree of SFDM halo models After 1998 Fuzzy, SFDM, Repulsive, Fluid, quintessence Various potentials for scalar field Boson star model 1992 1st SFDM model Lee & Koh Scalar field theory + relativity 1992 BEC model Newtonian+quantum Mech. Sin

  6. Rotation velocity r BEC model of DM Halos Sang-jin Sin ( PRD 50, 3650 (1994), hep-ph/9205208) • Dark matter halos are in BEC (Bose-Einstein Condensation) •  single mascroscopic wavefunction •  Halo as a “giant atom” • Uncertainty principle prevents collapse & small structures PNGB? GPE QM model Ripple Flat RC

  7. Boson star (SFDM) model of DM Halos I Lee and Koh (PRD 53, 2236,1996, hep-ph/9507385) • Generalize BEC model • BEC model+ general relativity + self interactionof DM particles • in scalar fieldtheory • Evan a tiny self-interaction matters! • First SFDM model for galacticdark matter “Galactic halo as a soliton star”, Abstracts, bulletin of the Korean Physical Society, 10 (2) (1992). • Allows wider mass range These two models have been rediscovered by many teams later  Fuzzy (2000), Repulsive, Scalar field (1998), Fluid…

  8. Boson star model of DM Halos II JWLee and IGKoh (PRD 53, 2236 (1996)) Action Metric Field Equation Gives similar curve of BEC model for weak gravity

  9. Cusp Problem • CDM simulation • NFW profile • density~1/r (cusp) NFW dSph Rotation curves  density Gilmore et al, APJ 663:948 (2007) • BEC/SFDM • density~ constant. at core

  10. BEC & Boson star models explain rotation curve of Dwarf Galaxies BEC (thus SFDM) model reproduces rotation curves of 12 LSB & dwarf galaxies very well (Boehmer & Harko, JCAP 06 (2007) 025)

  11. Contradictive behavior in cluster collisions Collisional Collisionless star DM+gas DM+star gas wikipedia Mahdavi etal Bullet cluster Abel520 CDM or MOND could hardly resolve this problem

  12. Newtonian Limit Gravity Scalar

  13. Boson star collision D. Choi, PRA,66,03609, D. Choi etal, preprint Bernal etal PRD74,103002 Palenzuela etal PRD 75, 064005 Solitonic E<0 Merging total E=K+W+I>0

  14. Main Idea: BEC DM halo collision star Stars are collisionless Dark Galaxy Galaxy without DM

  15. Observatonal Data Velocity=4700 km/s Separation=720 kpc Mass=10^14 solar mass Collision=100 Myr ago Velocity=1000 km/s Separation>400 kpc Mass=10^14 solar mass Collision=1Gyr ago Abel520 Bullet cluster We can determine l and m

  16. Size evolution & compact galaxy J. Lee, arXiv:0805.2877 NASA BEC/SFDM model Dokkum et al., APJ 677, L5 (2008).

  17. Minimum mass of dwarf galaxies Both DM and Baryonic contributes to M L. Strigari et al, Nature, 454, 1096 (2008) J. Lee in preparation

  18. Comparison between WIMP & BEC/SFDM This model can also explain "dark flow" announced yesterday!

  19. Candidates for dark energy • CC (w=-1) • Modified gravity • Quintessence (w>-1) • K-essence • Chaplygin gas • Phantom (w<-1) • Quintom (w>-1 w<-1) • Braneworld • Backreaction • Cosmic string • Vac. Energy • Quantum fluctuation • Surface tension • Holographic dark energy • …. and more Hard to cancel Zero point energy Holographic principle Entanglement DE d~1

  20. Evolution of our Dark energy idea Rh • Cancel Zero-point energy • Holographic principle • Cosmic horizon • Entanglement ~ Area JWLee,H.Kim,JJLee, JCAP08(2007)005 • Hawking radiation JWLee,H.Kim,JJLee, arXiv:0803.1987 Entangled Cosmic event horizon • Inflation with N~65 solves the cosmic coincidence problem • JJLee, HCKim, JWLee , PLB 661 (2008) 67

  21. Hawking radiation in de Sitter universe 1) gives dark energy but too small 2) different from thermal radiation But With UV cut-off Mp !

  22. Hawking radiation vs Black body radiation Cosmic Hawking radiation BB radiation r R adiabatic

  23. Prokopec "They've come up with an interesting physical mechanism for how [virtual particles] could lead to dark energy, They have chosen a very reasonable value for this, but if it turns out that this value is slightly wrong, it could throw off all their predictions " Seth Lloyd "I think they could really be onto something," Newscientist 2007 October

  24. Where does negative pressure come from? perfect fluid 1st-law If total energy increases as the universe expands, this matter has a negative pressure is an increasing function of t for d >0 P < 0

  25. Hawking radiation explains • why dark energy is so homogeneous and does not interact with ordinary matter. • simple-minded use of the spherical volume to calculate DE • linking the global property of the horizon to local DE • gravitational field detects the energy density of the radiation from the horizon. • energy from vacuum fluctuation Its wavelength is simply too long!

  26. No-free parameter model JWLee,HCKim,JJLee,hep-th/0709.0047 Hawking-Gibbons Holographic principle No free energy gain d =1! Observation Assume our universe is quasi-de Sitter universe.

  27. Dark energy parameter J.-Q. Xia et al arXiv:0708.1111 (2007). JWLee,H.Kim,JJLee, arXiv:0803.1987

  28. Conclusions • DM in BEC/scalar field can explain • many observed properties of DM • DE from Hawking radiation/Entanglement • can explain the mysteries of DE Both DM & DE may have quantum nature! Thank you very much

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