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!