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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
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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
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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
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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
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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.
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...
...
Blumenthal, Faber, Primack, & Rees 1984
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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
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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
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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)
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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
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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
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Also Agrees with Double Dark Theory!
Max Tegmark
P(k)
Distribution of Matter
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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
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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
as- sembly 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.
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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
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WMAP+SN+Clusters Determination of8 and M
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WMAP7
WMAP+SN+Clusters Determination of8 and M
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BOLSHOI SIMULATION FLY-THROUGH
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1NMSU, 2UCSC
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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
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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
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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
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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.
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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.
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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.
Milky Way:Triaxial Dark Halo(LM10)
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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
Primack Rio Lectures 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.
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Aquarius Simulation: Formation of a Milky-Way-size Dark Matter Halo
Diameter of Milky Way Dark Matter Halo1.6 million light years
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500 kpc
Diameter of visible Milky Way30 kpc = 100,000 light years
Diameter of Milky Way Dark Matter Halo1.6 million light years
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S t llit
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SatellitesThe discovery of many faint Local Group dwarf galaxies is
consistent with CDM predictions. Satellites, reionization,
lensing, and Ly forest data imply that WDM must be Tepidor Cooler.
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
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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
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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
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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 -
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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 -
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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
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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
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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 -
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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
Primack Rio Lectures 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.
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http://hipacc ucsc edu
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http://hipacc.ucsc.edu
http://hipacc.ucsc.edu/http://hipacc.ucsc.edu/ -
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