scalar field dark matter and evolution of galaxies 2) dark energy from cosmic hawking radiation
DESCRIPTION
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). - PowerPoint PPT PresentationTRANSCRIPT
OutlineOutline
• Dark Matter is in BEC or coherent Scalar field (1992)
• Dark energy comes from quantum entanglement or cosmic Hawking radiation. (2007)
universe theof size ~
galaxy theof size ~
Problems of CDM modelProblems of CDM model
CDM model is very successful at the scale larger than galaxies. But
1. Missing satellite galaxy problem 2. Cusp problem (rotation curve)3. Angular momentum catastrophe
Ostriker and Steinhardt Science 300, 20 (2003)
Solution:1) DM playing a role of CDM at the scale larger than galaxies, and atthe same time
2) suppressing sub-galactic structures.
BEC/SFDMBEC/SFDM
=> Min. Length scale!
Dark matter candidatesDark matter candidates
BEC/Scalar field,
Repulsive, Fluid
BEC model
Boson star model
Fuzzy, SFDM, Repulsive, Fluid, quintessence
Evolution tree of SFDM halo modelsEvolution tree of SFDM halo models
Scalar field theory + relativity
Various potentials for scalar field
1992
1992
After 1998
1st SFDM model1st SFDM model
Newtonian+quantum MechNewtonian+quantum Mech.
Sin
Lee & Koh
BEC model of DM HalosBEC model of DM Halos
PNGB?24haloCompton wavelength ~ R 10m eV
Dark matter halos are in BEC (Bose-Einstein Condensation) single mascroscopic wavefunction Halo as a “giant atom” Uncertainty principle prevents collapse & small structures
GPE
Rotation velocity
r
Ripple
QM model
Sang-jin Sin ( PRD 50, 3650 (1994), hep-ph/9205208)
Flat RC
Boson star (SFDM) model of DM Halos IBoson star (SFDM) model of DM Halos I
-26 310 10eV m eV
These two models have been rediscovered by many teams later Fuzzy (2000), Repulsive, Scalar field (1998), Fluid…
Lee and Koh (PRD 53, 2236,1996, hep-ph/9507385)
Generalize BEC model BEC model+ general relativity + self interaction of DM particles in scalar field theoryEvan a tiny self-interaction matters!
First SFDM model for galactic dark matter “Galactic halo as a soliton star”, Abstracts, bulletin of the Korean Physical Society, 10 (2) (1992).
Allows wider mass range
Boson star model of DM Halos IIBoson star model of DM Halos II JWLee and IGKoh (PRD 53, 2236 (1996))
Gives similar curve of BEC model for weak gravity
ActionMetricField
Equation
Cusp Problem Cusp Problem
Gilmore et al, APJ 663:948 (2007)
• CDM simulation NFW profile density~1/r (cusp)
NFW
Rotation curves density
dSph
•BEC/SFDM density~ constant. at core
BEC & Boson star models explain rotation BEC & Boson star models explain rotation curve of curve of Dwarf GalaxiesDwarf Galaxies
BEC (thus SFDM) model reproduces rotation curves of 12 LSB & dwarf galaxies very well (Boehmer & Harko, JCAP 06 (2007) 025)
Contradictive behavior in cluster collisionsContradictive behavior in cluster collisions
Bullet clusterAbel520
DM+starstar gas
CDM or MOND could hardly resolve this problem
starstar DM+gasCollisionlessCollisional
wikipedia
Mahdavi etal
Newtonian LimitNewtonian Limit
GravityScalar
Boson star collisionBoson star collision
D. Choi, PRA,66,03609,D. Choi etal, preprint
Bernal etalPRD74,103002
Palenzuela etal PRD 75, 064005
SolitonicMergingtotal E=K+W+I>0 E<0
0 Repulsive
Main Idea: BEC DM halo collisionMain Idea: BEC DM halo collision
starstar0 Repulsive
Stars are collisionless
Galaxy without DMDark Galaxy
Observatonal DataObservatonal Data
Bullet cluster Abel520
Velocity=4700 km/sSeparation=720 kpcMass=10^14 solar massCollision=100 Myr ago
Velocity=1000 km/sSeparation>400 kpcMass=10^14 solar massCollision=1Gyr ago
We can determine and m
Size evolution & compact galaxySize evolution & compact galaxy
~ 1/m ~1/Hsize
J. Lee, arXiv:0805.2877
NASABEC/SFDM modelDokkum et al., APJ
677, L5 (2008).
Minimum mass of dwarf galaxiesMinimum mass of dwarf galaxies
L. Strigari et al, Nature, 454, 1096 (2008)
~ 1/m p~1/ ~ / ~ /GM R GM
J. Lee in preparation
Both DM and Baryoniccontributes to M
Comparison between WIMP & BEC/SFDM Comparison between WIMP & BEC/SFDM
WIMP BEC/SFDMParticle model O PNGB, moduli?Relic density O ?Structure stability O rotating?Structure formation
O O
Cusp ? OMissing satellite ? OAngular momentum
? O
Compact galaxy ? OCluster collision ? OMinimum size ? ODark galaxy ? O
This model can also explain "dark flow" announced yesterday!
Candidates for dark energyCandidates 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 energyHolographic dark energy•…. and more
Hard to cancelZero point energy
d~1
Holographicprinciple
Evolution of our Dark energy ideaEvolution of our Dark energy idea
Cancel Zero-point energyHolographic principleCosmic horizonEntanglement ~ AreaJWLee,H.Kim,JJLee, JCAP08(2007)005
Hawking radiation JWLee,H.Kim,JJLee, arXiv:0803.1987
Rh
Entangled
• Inflation with N~65 solves the cosmic coincidence problem JJLee, HCKim, JWLee , PLB 661 (2008) 67
Cosmic event horizon
Hawking radiation in de Sitter universeHawking radiation in de Sitter universe
But With UV cut-off Mp
4 !T g H p
!
1) gives dark energy but too small2) different from thermal radiation
Hawking radiation vs Black body radiationHawking radiation vs Black body radiation
R
3
3
43
1~
~
~ ~ .
1~ ~
~ ~
TR
s T
S sR const
E STR
ET
R
2 2
2 23
1~ ~
~ ~Area holographic principle
~ ~
~ ~ ~ holographic DE
P
T Hr
S M r
E ST r
rr T
r
Cosmic Hawking radiationBB radiation
adiabatic
r
"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 "
Prokopec
Seth Lloyd "I think they could really be onto something,"
Newscientist 2007 October
Where does negative pressure come from?Where does negative pressure come from?
3
2
( )
( 3 )
d Rp
dR R
2 2
2
3 P
h
d M
R
perfect fluid
If total energy increases as the universe expands, this matter has a negative pressure
2
1 1d
HR dR HR
is an increasing function of t for d >0
2 8
3
GH
P < 0
1st-law
Hawking radiation explainsHawking 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!
JWLee,HCKim,JJLee, hep-th/0709.0047
Holographic principle
Hawking-Gibbons
No free energy gain
d =1!
No-free parameter model
Assume our universe is quasi-de Sitter universe.
Observation
Dark energy parameterDark energy parameter
JWLee,H.Kim,JJLee, arXiv:0803.1987
J.-Q. Xia et al arXiv:0708.1111 (2007).
ConclusionsConclusions
• DM in BEC/scalar field can explain many observed properties of DM
• DE from Hawking radiation/Entanglement can explain the mysteries of DE
Thank you very much
Both DM & DE may have quantum nature!