Successes of and Challenges to the "Double Dark" (DM+DE) ΛCDM Theory

8/6/2019 Successes of and Challenges to the "Double Dark" (DM+DE) CDM Theory

1/44

NINTH UCLA SYMPOSIUM ON SOURCES ANDDETECTION OF DARK MATTER AND DARK ENERGYIN THE UNIVERSE

Successes of and Challenges to the

"Double Dark" (DM+DE) CDM Theory

Joel Primack

UCSC


2/44

A Brief History of Dark Matter

1980 - Most astronomers are convinced that dark matter existsaround galaxies and clusters

1992 - COBE discovers CMB fluctuations as predicted by CDM;CHDM andCDM are favored CDM variants

1930s - Discovery that clusterV~ 1000 km/s

1970s - Discovery of flat galaxy rotation curves

1983-84 - Cold Dark Matter (CDM) theory proposed

1998 - SN Ia and other evidence ofDark Energy

2003-10 - WMAP and LSS data confirmCDM predictions

~2010 - Discovery of dark matter particles??

2000 -CDM is the Standard Cosmological Model

1980-84 - short life of Hot Dark Matter (HDM) theory

1982 - Supersymmetric Dark Matter proposed


3/44

A Brief History of Dark Matter

1980 - Most astronomers are convinced that dark matter existsaround galaxies and clusters

1992 - COBE discovers CMB fluctuations as predicted by CDM;CHDM andCDM are favored CDM variants

1930s - Discovery that clusterV~ 1000 km/s

1970s - Discovery of flat galaxy rotation curves

1983-84 - Cold Dark Matter (CDM) theory proposed

1998 - SN Ia and other evidence of Dark Energy

2003-10 - WMAP and LSS data confirmCDM predictions

~2010 - Discovery of dark matter particles??

2000 -CDM is the Standard Cosmological Model

1980-84 - short life of Hot Dark Matter (HDM) theory

1982 - Supersymmetric Dark Matter proposed


4/44

1967 - Lynden-Bell: Violent relaxation (also Shu 1978)1976 - Binney, Rees & Ostriker, Silk: Cooling curves1977 - White & Rees:galaxy formation in massive halos1980 - Fall & Efstathiou:galactic disk formation in massive halos1982 - Guth & Pi; Hawking; Starobinski: Cosmic Inflation P(k) = k1

1982 -Pagels & Primack:Lightest SUSY particle stable by R-parity:Gravitino

1982 - Blumenthal, Pagels, & Primack; Bond, Szalay, & Turner: WDM

1982 -Peebles: CDM P(k) - simplified treatment (no light neutrinos)

1983 -Blumenthal & Primack; Bond & Szalay: CDM , WDM P(k)

1983 -Goldberg:Photino as SUSY CDM particle1983 -Preskill, Wise, & Wilczek; Abbott & Sikivie; Dine & Fischler:Axion CDM1984 -Blumenthal, Faber, Primack, & Rees: CDM compared to CfA survey

1984 -Peebles; Turner, Steigman, Krauss: effects of

HDM Galaxy Distribution CDM White 1986

1984 -Ellis, Hagelin, Nanopoulos, Olive, & Srednicki:Neutralino CDM

1985 -Davis, Efstathiou, Frenk, & White: 1

st

CDM,

CDM simulations

Early History of Cold Dark Matter

Ruled Out Looks OK

Primack Rio Lectures 2009


5/44

Some steps toward cosmic structure formationMany people thought the early universe was complex (e.g.mixmaster universeMisner, explosions Ostriker, ).

But Zeldovichassumed that it is fundamentally simple, with justa scale-free spectrum of adiabatic fluctuations of

(a) baryons

and when that failed [(T/T)CMB < 10-4] and Moscow physicists

thought they had discovered neutrino mass(b) hot dark matter.

Blumenthal and I thought simplicity a good approach, but wetried other simple candidates for the dark matter, first

(c) warm dark matter, and then, with Faberand Rees,(d) cold dark matter, which moved sluggishly in the early

universe.


6/44


7/44

...

...

Blumenthal, Faber, Primack, & Rees 1984


8/44

CDMSphericalCollapse

Model

Primack & Blumenthal 1983based on CDM, cooling theoryofRees & Ostriker 1977, Silk1977, Binney 1977 andbaryonic dissipation within darkhalosWhite & Rees 1978

Cooling curves

zero metallicity

solar metallicity

Explains WhyGalaxies Exist


9/44

CDM Structure Formation: Linear Theory

Primack & Blumenthal 1983

outside horizon

inside horizon

Blumenthal, Faber, Primack, & Rees 1984

Matter fluctuations that enter the horizon during the

radiation dominated era, with masses less than about

1015 , grow only log a, because they are not inthe gravitationally dominant component. But matter

fluctuations that enter the horizon in the matter-

dominated era grow a. This explains the

characteristic shape of the CDM fluctuation

spectrum, with (k) k-n/2-2 log k

Cluster and smaller-scale fluctuations damp

because of free-streaming


10/44

RelativeHeight

Deuterium Abundance+ Big Bang Nucleosynthesis

WMAPCosmic

Microwave

Background

Angular Power Spectrum

Galaxy Cluster in X-rays

Absorption of Quasar Light

5 INDEPENDENT MEASURESAGREE: ATOMS ARE ONLY~4.5% OF COSMIC DENSITY

& BAO WIGGLES IN GALAXY P(k)


11/44

Dark Energy 72%

Cold Dark Matter 23%

Invisible Atoms 4%

H and He 0.5%

All Other Atoms 0.01% Visible Matter 0.5%}

CDM

DoubleDark

Theory


12/44

WMAP 7-YEAR DATAReleased January 2010

Big Bang Data Agrees with Double DarkTheory!

COBE

POWER

l

90

Wilkinson MicrowaveAnisotropy Probe

WMAP2003-

CosmicBackground

ExplorerCOBE1992

WMAP 7-YEAR DATAReleased January 2010

ACBAR

QUaD

Ground-Based

Data

Double Dark Theory

ACBAR

QUaD

0.2 0.1 Angular Scale0.52 1


13/44

Also Agrees with Double Dark Theory!

Max Tegmark

P(k)

Distribution of Matter


14/44

Text Text Text

Text Text Text

Text

Text Text Text

Text Text Text

Text

Text Text Text

WMAP1

WMAP-only Determination of8 and M

2003

Th Mill i R


15/44

Springel et al. 2005

The Millennium Run properties ofhalos (radialprofile,concentration,shapes) evolution of thenumber density

of halos, essentialfor normalization of

Press-Schechter-

type models

evolution of thedistribution andclustering ofhalosin real andredshift space, for

comparison with

observations accretionhistory of halos,assembly bias

(variation of large-

scale clustering with

assembly history),

and correlation with

halo properties

including angular

momenta andshapes

halo statisticsincluding the mass

and velocity

functions, angular

momentum and

shapes, subhalo

numbers and

distribution, and

correlation with

environment

void statistics,including sizes and

shapes and theirevolution, and theorientation of halospins around voids

quantitativedescriptions of the

evolving cosmicweb, includingapplications to weak

gravitational lensing

preparation ofmock catalogs,essential foranalyzing SDSS

and other surveydata, and forpreparing for new

large surveys fordark energy etc.

merger trees,essential for semi-analyticmodeling of theevolving galaxypopulation, including

models for thegalaxy merger rate,

the history of starformation andgalaxy colors andmorphology, the

evolving AGNluminosity function,stellar and AGN

feedback, recycling

of gas and metals,etc.


16/44

Text Text Text

Text Text Text

Text

Text Text Text

Text Text Text

Text

WMAP1

WMAP3

WMAP5

WMAP7

WMAP-only Determination of8 and M

2003

2006

2008

2010


17/44

WMAP+SN+Clusters Determination of8 and M


18/44

WMAP7

WMAP+SN+Clusters Determination of8 and M


19/44


20/44


21/44

BOLSHOI SIMULATION FLY-THROUGH


22/44

1NMSU, 2UCSC


23/44

The Millennium-I Run(Springel+05) was a landmarksimulation, and it has been the basis for ~300 papers.However, it and the new Millennium-II simulations were runusing WMAP1 (2003) parameters, and the Millennium-Iresolution was inadequate to see many subhalos. The new

Bolshoi simulation (Klypin, Trujillo & Primack 2010) used theWMAP5 parameters (consistent with WMAP7) and has nearlyan order of magnitude better mass and force resolution thanMillennium-I. We have now found halos in all 180 storedtimesteps, and we have complete merger trees. We areworking with Stefan Gottloeber, Risa Wechler, and Mike Bushaon halo and merger trees, and with Darren Croton, Rachel

Somerville, Lauren Porter and Andrew Benson on semi-analyticmodels of the evolving galaxy population based on Bolshoi.

Halos and galaxies: results from the Bolshoi simulation

Cosmological Parameters

Power Spectrum

Fraction of z = 0

Halos Tracked to

Given Redshift

200

50

km/s

Halo Concentration

at z = 0, 0.5, 1, 2, 3, 5

upturn!

Millennium

Bolshoi

z =

0

0.5

1

2

3

5

100


24/44

Mass Function of

Distinct Halos

Velocity Function of

Distinct Halos

at z = 0, 2, 3, 5, 6.5

Tully-Fisher RelationSubhalos follow

the dark matter

distribution

except in theinner regions of

cluster and

galaxy halos

Curves:

Sheth-Tormen

approx.

NOTE:

figures are

from Klypin,

Trujillo, &

Primack,

arXiv:

1002.3660

(Mon Feb 22)

z = 10 6 2.5 0 z = 6.5 5 3 2 0

Clusters

Galaxies

10x


25/44

Dark halos aremore elongatedthe moremassive they areand the earlierthey form. Wefound that thehalo scalesas a power-lawin Mhalo/M*.These results

are fromAllgood+2006.Our new Bolshoisimulation hasbetter resolution

in a volume 103

times larger.

Halo Shapes

z=0

z=2

z=1

s =

short axis

long axis


26/44

Milky Way:Triaxial Dark Halo(LM10)

The tidal debris of the

Sagittarious dwarf

galaxy constrains the

shape of the Milky Waydark matter halo.

Recent work by

David Law et al.

finds a triaxial

halo, in general

agreement with

CDM.


27/44


Sagittarious dwarf



Recent work by

David Law et al.

finds a triaxial

halo, in general

agreement with

CDM.


28/44


Sagittarious dwarf



Recent work by

David Law et al.

finds a triaxial

halo, in general

agreement with

CDM.

Milky Way:Triaxial Dark Halo(LM10)


29/44

Satellites

Cusps

Angular momentum

small scale issues

Triaxial dark matter halos, observational biases, and newsimulations suggest that observed velocity structure of LSB

and dSpiral galaxies are consistent with cuspy CDM halos.WDM doesnt resolve cusp issues.

CDM simulations are increasingly able to form realisticspiral galaxies, as resolution improves and feedback

becomes more realistic.

Primack NJP 2009


The discovery of many faint Local Group dwarf galaxies isconsistent with CDM predictions. Satellites, reionization,

lensing, and Ly forest data imply that WDM must be Tepidor Cooler.


30/44

Aquarius Simulation: Formation of a Milky-Way-size Dark Matter Halo

Diameter of Milky Way Dark Matter Halo1.6 million light years


31/44

500 kpc

Diameter of visible Milky Way30 kpc = 100,000 light years

Diameter of Milky Way Dark Matter Halo1.6 million light years


32/44

S t llit


33/44

SatellitesThe discovery of many faint Local Group dwarf galaxies is

consistent with CDM predictions. Satellites, reionization,


New DevelopmentsThe Aquarius simulations have not quite enough substructureto explain quad-lens radio quasar flux anomalies -- butperhaps including baryons in simulations will help.

Milky-Way-size halos in low-density regions have fewer DMsatellites, according to new simulations.

CDM predicts that there is a population of low-luminositystealth galaxies around the Milky Way.

Th A i i l ti h t it h b t t


34/44

The Aquarius simulations have not quite enough substructureto explain quad-lens radio quasar flux anomalies -- butperhaps including baryons in simulations will help.

Contour map of the subhalo surface massdensity fraction, which is the ratio of thesurface mass in subhaloes to that in the totalhalo, from Aquarius-D-2 simulation.

Mean subhalo surface mass fractionvs. radius.

Estimate fromMao+04

90% C.L.

Effects of dark matter substructures on gravitational lensing: results from the Aquarius simulations

D. D. Xu, Shude Mao, Jie Wang, V. Springel, Liang Gao, S. D. M. White, Carlos S. Frenk, Adrian Jenkins,Guoliang Li and Julio F. Navarro Mon. Not. R. Astron. Soc. 398, 12351253 (2009)

6 Aquarius Dsimulations

Milky-Way-size halos have large variation in number of DM


35/44

Milky Way size halos have large variation in number of DMsatellites, according to new simulations.

Subhalo-poor halo z=0

Subhalo-rich halo z=0

Variation of the Subhalo Abundance in Dark Matter Halos

Galaxy halos formed earlier have higher concentration and smaller number of subhalos at present .

ApJ, 696, 2115 (2009)

Subhalo-rich halo z=1

Subhalo-poor halo z=1

1.6 Mpc

1.6 Mpc

0.8 Mpc

0.8 Mpc

Halo Concentration

3 10

1.5 3HaloMass

CDM predicts that there is a population of low-luminosity stealth


36/44

CDM predicts that there is a population of low-luminosity stealthgalaxies around the Milky Way.

STEALTH GALAXIES IN THE HALO OF THE MILKY WAYJames S. Bullock, Kyle R. Stewart, Manoj Kaplinghat, and Erik J. Tollerud

We predict that there is a population of low-luminosity dwarf galaxies with luminositiesand stellar velocity dispersions that are similar to those of known ultrafaint dwarfgalaxies but they have more extended stellar distributions (half light radii greater thanabout 100 pc) because they inhabit dark subhalos that are slightly less massive than theirhigher surface brightness counterparts. One implication is that the inferred common massscale for Milky Way dwarfs may be an artifact of selection bias. A complete census of theseobjects will require deeper sky surveys, 30m-class follow-up telescopes, and more refined

methods to identify extended, self-bound groupings of stars in the halo.

2009arXiv0912.1873B

CDM predicts that there is a population of low-luminosity stealth
http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009arXiv0912.1873B&db_key=PRE&link_type=ABSTRACT&high=49fdcc56ac01273http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009arXiv0912.1873B&db_key=PRE&link_type=ABSTRACT&high=49fdcc56ac01273


37/44

CDM predicts that there is a population of low-luminosity stealthgalaxies around the Milky Way.

STEALTH GALAXIES IN THE HALO OF THE MILKY WAYJames S. Bullock, Kyle R. Stewart, Manoj Kaplinghat, and Erik J. Tollerud

We predict that there is a population of low-luminosity dwarf galaxies with luminositiesand stellar velocity dispersions that are similar to those of known ultrafaint dwarfgalaxies but they have more extended stellar distributions (half light radii greater thanabout 100 pc) because they inhabit dark subhalos that are slightly less massive than theirhigher surface brightness counterparts. One implication is that the inferred common massscale for Milky Way dwarfs may be an artifact of selection bias. A complete census of theseobjects will require deeper sky surveys, 30m-class follow-up telescopes, and more refined

methods to identify extended, self-bound groupings of stars in the halo.

2009arXiv0912.1873B

SatelliteInfall

redshift
http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009arXiv0912.1873B&db_key=PRE&link_type=ABSTRACT&high=49fdcc56ac01273http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009arXiv0912.1873B&db_key=PRE&link_type=ABSTRACT&high=49fdcc56ac01273


38/44

CuspsTriaxial dark matter halos, observational biases, and new

simulations suggest that observed velocity structure of LSBand dSpiral galaxies are consistent with cuspy CDM halos.WDM doesnt resolve cusp issues.

New Developments New simulations show that gas motions or dynamical friction

during evolution of dwarf spiral galaxies can remove cusps.

The properties of density cores of dwarf spiral galaxies areinconsistent with expectations fromWDM.

New simulations show that gas motions or dynamical friction


39/44

New simulations show that gas motions or dynamical frictionduring evolution of dwarf spiral galaxies can remove cusps.

Bulgeless dwarf galaxies and dark matter cores from supernova-driven outflows

F. Governato, C. Brook, L. Mayer, A. Brooks, G. Rhee, J. Wadsley, P. Jonsson, B. Willman, G. Stinson, T. Quinn & P. Madau Nature 463, 203 (Jan 2010)

Most observed dwarf galaxies consist of a rotating stellar disk embedded in a massive dark-matter halo with anear-constant-density core. Models based on CDM, however, invariably form galaxies with dense spheroidalstellar bulges and steep central dark-matter profiles, because low-angular-momentum baryons and darkmatter sink to the centers of galaxies through accretion and repeated mergers. Here we reporthydrodynamical simulations in which the inhomogeneous interstellar medium is resolved. Strong outflowsfrom supernovae remove low-angular-momentum gas, which inhibits the formation of bulges anddecreases the dark-matter density to less than half of what it would otherwise be within the central

kiloparsec. The analogues of dwarf galaxiesbulgeless and with shallow central dark-matter profilesarise naturally in these simulations. Simulations using the same implementation of star formation andfeedback reproduce some global scaling properties of observed galaxies across a range of masses andredshifts.

z = 1.5

4

2

0

2

4

4 2 0 2 4

4

2

0

2

4

4 2 0 2 4

4

2

0

2

4

8 4 0 4 8

Kiloparsecs

26 25 24 23 22 21M per arcsec2

Gas outflows Face-on i-band image Edge-on i-band image

The Case Against Warm or Self-Interacting Dark Matter as Explanations for


40/44

Rachel Kuzio de Naray, Gregory D. Martinez, James S. Bullock, Manoj Kaplinghat

The Case Against Warm or Self-Interacting Dark Matter as Explanations for

Cores in Low Surface Brightness Galaxies 2010, ApJ, 710L, 161

Warm dark matter (WDM) and self-interacting dark matter (SIDM) are often motivated bythe inferred cores in the dark matter halos of low surface brightness (LSB) galaxies. We

test thermal WDM, non-thermal WDM, and SIDM using high-resolution rotation curves ofnine LSB galaxies. If the core size is set by WDM particle properties, then even thesmallest cores we infer would require primordial phase space density values thatare orders of magnitude smaller than lower limits obtained from the Lyman alphaforest power spectra. We also find that the dark matter halo core densities vary by afactor of about 30 while showing no systematic trend with the maximum rotation velocityof the galaxy. This strongly argues against the core size being directly set by large self-

interactions (scattering or annihilation) of dark matter. We therefore conclude that theinferred cores do not provide motivation to preferWDM orSIDM over other darkmatter models.

We fit these dark mattermodels to the data anddetermine the halo core radiiand central densities. Whilethe minimum core size inWDM models is predicted todecrease with halo mass, wefind that the inferred core radiiincrease with halo mass andalso cannot be explained witha single value of the primordial

phase space density.

ll l i Primack NJP 2009
http://arxiv.org/find/astro-ph/1/au:+Kaplinghat_M/0/1/0/all/0/1http://arxiv.org/find/astro-ph/1/au:+Kaplinghat_M/0/1/0/all/0/1http://arxiv.org/find/astro-ph/1/au:+Bullock_J/0/1/0/all/0/1http://arxiv.org/find/astro-ph/1/au:+Bullock_J/0/1/0/all/0/1http://arxiv.org/find/astro-ph/1/au:+Martinez_G/0/1/0/all/0/1http://arxiv.org/find/astro-ph/1/au:+Martinez_G/0/1/0/all/0/1http://arxiv.org/find/astro-ph/1/au:+Naray_R/0/1/0/all/0/1http://arxiv.org/find/astro-ph/1/au:+Naray_R/0/1/0/all/0/1


41/44

Satellites

Cusps

Angular momentum

small scale issues

Triaxial dark matter halos, observational biases, and newsimulations suggest that observed velocity structure of LSB

and dSpiral galaxies are consistent with cuspy CDM halos.WDM doesnt resolve cusp issues.

CDM simulations are increasingly able to form realisticspiral galaxies, as resolution improves and feedback

becomes more realistic.

Primack NJP 2009


The discovery of many faint Local Group dwarf galaxies isconsistent with CDM predictions. Satellites, reionization,



42/44

http://hipacc ucsc edu
http://hipacc.ucsc.edu/


43/44

http://hipacc.ucsc.edu
http://hipacc.ucsc.edu/http://hipacc.ucsc.edu/


44/44

Successes of and Challenges to the "Double Dark" (DM+DE) ΛCDM Theory

Documents

Transcript of Successes of and Challenges to the "Double Dark" (DM+DE) ΛCDM Theory