Profound Connections Between Quarks and the Cosmos
1. 2009 Biermann Lectures:
“Quarks and the Cosmos”
I. Cosmic Acceleration and Dark Energy (8 July)
I. Inflation and Beyond (23 July)
II. Future Opportunities and Challenges (28 July)
July 2009
MPA-Garching
Michael S. Turner
Kavli Institute for Cosmological Physics
The University of Chicago
2. • Contributions to the theory of
convection in stars
• Modeled the solar
chromosphere and corona
• Computed atomic physics
parameters needed for stars
• Predicted the solar wind
(based upon comets)
• Magnetic fields in the solar
system and in the Galaxy
Where is he now?
6. 11992299:: JJuusstt OOnnee NNuummbbeerr KK
(error bars not needed, velocity in km)
K (H0) = 550 km/s/Mpc
HHuubbbbllee && HHuummaannssoonn:: ffeeww 110000 ggaallaaxxiieess,, zz << 00..11
Michael S Turner
12. and at U Mass
The Redbook, a manual for faculty members
that explained what a university was, and
what it wasn't. It cited two courses one
wouldn't find in a curriculum of higher
education: witchcraft and cosmology.
Michael S Turner
17. TTwwoo RReeaallllyy IImmppoorrttaanntt IIddeeaass
TThhaatt CChhaannggeedd CCoossmmoollooggyy
with deep connections between quarks and the cosmos
IInnffllaattiioonn:: brief period of rapid
(accelerated) expansion accounts for
smoothness, flatness; heat of the big
bang; and seed inhomogeneities
PPaarrttiiccllee ddaarrkk mmaatttteerr:: bulk of the dark
matter that holds the Universe together
resides in a sea of elementary particles
left over from the big bang
Michael S Turner
18. Cold Dark Matter Transformed
“Astrophysical Cosmology”
… and this Institute!
Michael S Turner
19. 1990s: BBeeggiinnnniinngg ooff DDaattaa--ddrriivveenn
CCoossmmoollooggyy
• COBE! and CMB experiments
• Redshift surveys (CfA, IRAS, 2dF, SDSS)
• Large-scale velocity field measurements
• Gravitational lensing
• Big telescopes (Keck, …) with big CCD
cameras
• HST, X-ray, gamma-ray, IR, …
Michael S Turner
45. Clusters aass SSttaannddaarrdd RRuulleerrss
Use constancy of
the baryon-to-total
mass ratio as a
standard ruler
S. Allen et al, MNRAS 353, 457 (2004); 383, 879 (2007)
46. New stand alone evidence for
cosmic acceleration from
clusters observed by Chandra
A.Vikhlinin et al, ApJ 692, 1060 (2009) [arXiv:0812.2720]
36 Clusters w/<z>~0.55 and 49 w/<z>~0.05
Michael S Turner
52. Very elastic
stuff (p < -ρ/3)
with repulsive
gravity is
called “dark
energy”
53. DDaarrkk EEnneerrggyy
Defining features:
• Large negative pressure, p ~ -ρ, so
that (ρ + 3 p) < 0
• w = p/ρ (equation-of-state parameter) ~ -1
• Smoothly distributed
• Not particulate (dark matter has p ~ 0)
Simplest example:
• Energy of the quantum vacuum: w = -1
54. The Gravity of
Nothing
Is Repulsive
… But How Much Does
Nothing Weigh?
Apparently, Way Too Much
or Possibly Nothing
to be more precise, the
answer is nonsensical
(infinite) – not as bad as a
finite answer that is off by
orders of magnitude
ρvac ≈ 3 x 10-11 eV4
56. Now we have two puzzles:
Why does nothing weighs so little?
&
What is dark energy?
Puzzles could be related or unrelated!
57.
58. Theorists:
When in
doubt, just
add a
scalar field
NB: does not
address of the
lightness of
nothing
59.
60.
61.
62. “Old Gravitational Physics” Hitherto
Undiscovered Aspects of GR?
• Primordial inflation explains why the universe is
accelerating today, E. W. Kolb, S. Matarrese, A. Notari,
A. Riotto (astro-ph/0503117)
• On cosmic acceleration without dark energy, E.W. Kolb,
S. Matarrese, A. Riotto (astro-ph/0506534)
• Comments on Backreaction and Cosmic Acceleration,
E. Kolb, S. Matarrese, A. Riotto (astro-ph/0511073)
• Cosmological background solutions and cosmological
backreactions, E. Kolb, V. Marra, S. Matarrese, (arXiv:
0901.4566)
63. Dark Theory Summary
• Can easily accommodate cosmic
acceleration (meets Eddington criterion)
• No satisfactory or even compelling
explanation (lots of interesting ideas)
• “GR exceptionalism” (hard to create a
viable alternative)
• Very important problem
64. WWhhyy ddaarrkk eenneerrggyy iiss iimmppoorrttaanntt
Not in the list of players in the standard model
(new physics)
Non-particulate (counterexample to the 2000 yr
reductionist approach), repulsive gravity
Could be related to inflation or dark matter or both
or neither!
May have other effects (long range forces,
neutrino mass)
Controls the destiny of the Universe (though
probably not evolution of structure etc)
66. Cannot Understand Our Cosmic
Destiny Until We Understand What
Dark Energy Is!
In the Presence of Dark
Energy, a Flat Universe
Can Expand Forever,
Re-collapse, or Even
Experience a Big Rip!
70. Current null hypothesis (Λ/quantum
vacuum energy) is not acceptable
(maybe enough for astrophysical
cosmologist).
It is a signal for new physics:
gravitational, particle, or ? And
fundamental to our understanding
of the cosmological framework
71. Important
clue or
coincidence?
At the very
least, we can
now say that
cosmology
is the battle
between two
dark titans
72. TTwwoo BBiigg DDaarrkk QQuueessttiioonnss
Does Dark Energy change with time
(i.e., is dark energy vacuum energy)?
No, at the 10 to 20% level
Does Cosmic Acceleration require
going beyond General Relativity?
Not well tested
73. Probing CCoossmmiicc AAcccceelleerraattiioonn
aanndd DDaarrkk EEnneerrggyy
• Primary effect is on the expansion rate
• Expansion rate controls distances, structure growth
• Two Qualitatively Different Probes
– Geometric: distances
– Dynamic: growth of structure
– NB: if not GR, changes in growth, lensing
74. Known PPrroobbeess ooff DDaarrkk EEnneerrggyy
• Supernovae: Geometric
• BAO: Geometric + simple physics
• Weak Lensing: Geometric + dynamic
• Clusters: Dynamics + geometric
• Evolution of large-scale structure (dynamic)
– Must reproduce LCDM
– Growth factor/red-shift space distortions
• CMB and other precision data that pin down
cosmological parameters (provide priors)
75. Where We Are Today
Dark Energy:
ΩDE = 0.76 ± 0.02
w = -0.94 ± 0.1
(± 0.1 sys)
77. No Reason to Believe w is Constant
Allow w to vary:
w = w0 + wa(1-a)
a = scale factor
ΩDE = 0.76 ± 0.02
w0 = -1 ± 0.2
wa ~ 0 ± 1
Possible variation is
not well constrained
78. Supernovae: SSiiggnniiffiiccaanntt PPrrooggrreessss
• Observational side
– >1000 SNeIa; better studied (more colors, esp. IR, spectra,
better LC coverage)
– Warts yes; cancer no
• Theoretical side
– Significant improvement in handling of combustion; ignition
mechanism still a big issue (source of diversity?)
– Producing more observables
– Evidence for 1.4 Msun explosion
– Tests for and models of SNeIa outliers
• Issues
– Dust, percent level photometry, need larger local sample/training
set; demographics, outliers,
– Better theoretical understanding
81. • Observational side
CClluusstteerrss
– Big surveys underway (ACT, SPT)
– First blind detections of clusters (SPT)
– Results from 400d: constraints to w & stand alone evidence for
DE
– Clusters can be found by O, X, and SZ
• Theoretical side
– Exponential leverage!
– Significant progress on understanding mass/observable relations
and formation history
• Open issues
– Robustness of mass/observable relations
– Selection
– Cluster physics: how much more than
82. Staniszewski et al, astro-ph/0810.1578
First Results from the
South Pole Telescope
84. • Observational side
BBAAOO
– Two (three) detections with 4% errors!
– Big surveys underway
– Need lots of “spectroscopic class” red shifts
• Theoretical side
– Powerful & clean; good probe of curvature
– Geometric + “simple physics”
• Open issues
– Exploit other scales (damp, Silk)
– Systematics: what are they??; how bad?? Small
compared to 1%
85. WWeeaakk LLeennssiinngg
• Observational side
– Steady progress ( 100 sq deg): signal out to 4
degrees (CFHTLS), on the way to 1000 sq deg and
beyond
– mild constraints on w; WMAP tension on σ8 gone
• Theoretical side
– Theory well understood, but γ ~ σ8 ΩM
0.4 z0.8 |w|0.15
– Shear ratio test isolates geometric side
• Issues
– Better knowledge of non-linear power spectrum
– Systematics (image, photo-z: δw ~ 15δz) – see
Taylor
86. Impressive AArrrraayy ooff DDaarrkk EEnneerrggyy
PPrroojjeeccttss oonn tthhee HHoorriizzoonn
(pssst, don’t tell Simon “DM” White)
• BAO: SDSS/2dF, WiggleZ, FMOS, BOSS HETDEX,
WFMOS, PAU
• CL: SZA, SPT, DES, ACT, 400d, eROSITA
• SNe: JDEM, DES, PanSTARRS
• WL: PS, JDEM, EUCLID, DES, PanSTARRS
• CMB et al: WMAP/ACT/SPT/Planck – cosmological
degeneracies make many other observations valuable
On the way to few % in w0, 10% in wa, significant tests of
underlying gravity theory … and deeper understanding of
dark energy
87. DDaarrkk SSuummmmaarryy
• Strong evidence for cosmic acceleration, central
part of consensus cosmology
• Theory provides a framework for discussing, but
not understanding
• Profound problem whose solution is likely to
have far reaching consequences
• Powerful probes: Clusters, SNe, BAO, WL +
Planck priors
• Cosmic complementarity:
– Kinematic and dynamic probes; error ellipses
– Expt’l complementarity: different systematics/risks
• Open mind to new ideas: long range force
90. 1. w = -1 & theory breakthrough
Percent level measurements of w and wa and LSS
consistent with ΛCDM
+
Theoretical understanding of small vacuum
energy
=
Problem Solved for Cosmologists and
Particle Physicists
91. 2. “w = -1” & theory breakthrough
Percent level measurements of w and wa and LSS
consistent with ΛCDM
+
New compelling theoretical prediction for time
variation of w and/or wa – just beyond the
reach of Stage IV
=
Problem Solved for Cosmologists,
Particle Physicists think about Stage V
92. 3. “w ≠ -1” or wa ≠ 0
Detection of signature that DE is not
vacuum energy
Potential implications for both particle
physics and cosmology
=
With or without theoretical breakthrough
both Cosmologists, Particle Physicists
think about what to measure in Stage V
93. 4. w = -1 & no theory breakthrough
Percent level measurements of w and wa and LSS
consistent with ΛCDM
+
No theoretical understanding of small vacuum
energy
=
Problem solved for cosmologists, but not for
particle physicists
“Time out”: take a break and think hard about
what to do next
95. EEaarrllyy CCoonnffuussiioonn
• 1917 – 1929
– Einstein: static, finite, positively curved Universe
ρM = 2ρΛ, R = 1/(4πG ρM)1/2
– de Sitter (1917): vacuum solution, first derivation
of Hubble’s Law
– Eddington-Lemaitre long lived cosmologies
– Hubble discovers expansion
– Einstein: “my greatest blunder”
– Eddington remains obsessed
96. RReevviivvaallss
• 1948 – 1970
– Bondi & Gold, Hoyle: Steady State Cosmology:
“perfect cosmology”
– Strong signs of evolution: quasars, radio sources
and CMB kills a beautiful theory
– Petrosian, Salpeter & Szekeres (abudnace of z ~ 2
QSOs) and Gunn & Tinsley (data)
– Rise of Standard Cosmology (Hot Big Bang)
97. QQuuaannttuumm VVaaccuuuumm EEnneerrggyy::
MMoosstt EEmmbbaarrrraassssiinngg PPrroobblleemm
iinn aallll ooff PPhhyyssiiccss
• 1930s: Pauli, “Size of Universe could not reach
to the moon”
• 1968: Zel’dovich articulates the problem
• 1989: Weinberg, “Bone in the throat of
theorists”
98. Most Anticipated SSuurrpprriissee EEvveerr
• 1981 – 1984: Inflation & CDM
• 1984 on – “Ω problem”
• 1984 – 1995: Λ solution, best fit
Universe, COBE and ΩM ~ 0.3 &
triumph of ΛCDM
• 1998: The Accelerating Universe
• 1998: Cosmology Solved Debate
• 1998: Birth of Dark Energy
and a new puzzle
Rapid acceptance
it is the missing piece of the puzzle
