Biermann - 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)
I. Future Opportunities and Challenges (28 July)
July 2009
MPA-Garching
Michael S. Turner
Kavli Institute for Cosmological Physics
The University of Chicago

2. CCoossmmoollooggyy
iiss aa
yyoouunngg sscciieennccee
… its story only begins 60 years
after Darwin, 300 years after the
invention of the telescope
Michael S Turner

3. Progress driven by
powerful ideas and
instruments
(especially last 25 years)
Michael S Turner

4. Gamow’s Hot Big Bang
“alpher, bethe, gamow,” 1948

5. Michael S Turner

6. 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

7. Cold Dark Matter Transformed
“Astrophysical Cosmology”
… and this Institute!
Michael S Turner

8. Profound
Connections
Between Quarks
and the Cosmos
Basic Features
of the Universe
tied to
Fundamental
Physics

9. TThhee ““CCoonnsseennssuuss CCoossmmoollooggyy””
based upon precision measurements
• From quark soup to nuclei and atoms to
galaxies and large-scale structure
• Flat, accelerating Universe; ΛCDM structure
formation
• Atoms, exotic dark matter & dark energy
• Consistent with inflation
• Precision parameters
–Ω0 = 1.005 ± 0.006 (uncurved)
–ΩM = 0.280 ± 0.013
–ΩB = 0.045 ± 0.0015
–ΩDE = 0.72 ± 0.015
–H0 = 70 ± 1.3 km/s/Mpc
–t0 = 13.73 ± 0.12 Gyr
–Nν = 4.4 ± 1.5
Michael S Turner

10. IInnffllaattiioonn::
TTiimmee ffoorr CCeelleebbrraattiioonn
oorr TTiimmee ffoorr aa CChhaannggee??
See, M.S. Turner, Nature Physics 4, 89 (2008)
Michael S Turner

11. Successes ooff SSttaannddaarrdd HHoott
BBiigg BBaanngg CCoossmmoollooggyy
circa 1980
• Expansion of the Universe
• Big-bang nucleosynthesis (BBN)
• Cosmic Microwave Background (CMB)
• Structure formation by gravitational
instability
“Reliable account of the Universe from
10-5 seconds until today”

12. BBiigg UUnnaannsswweerreedd QQuueessttiioonnss
circa 1980
• Origin of baryons
• Cosmological constant problem
• Before the big bang/initial singularity
• Nature of dark matter
• Dynamite behind the big bang
• Heat of the big bang
• Isotropy, homogeneity and flatness (not generic
initial conditions)
• Origin of seed inhomogeneity Addressed by Inflation

14. ““TTwwoo HHoorriizzoonn PPrroobblleemmss””

15. ““TTwwoo HHoorriizzoonn PPrroobblleemmss””
SSaaiidd AAnnootthheerr WWaayy
• Horizon at last scattering subtends only 1
degree on the sky; what mechanism causes the
temperature to be so uniform on scales » 1
degree?
• Galactic-sized masses entered the horizon
about 1 year after the big bang; what causal
physics created density perturbations that late in
the history of Universe?

16. CCoossmmiicc IInnffllaattiioonn
• Addresses isotropy, homogeneity &
inhomogeneity, flatness, dynamite, and
heat of the BB
• Lessens (does not eliminate) dependence
upon initial data
• Paradigm, not a model

17. TThhee 22 EElleemmeennttss ooff IInnffllaattiioonn
1. Period of exponential expansion (constant
Hubble Constant and horizon size)
“superluminal expansion’
1. Tremendous entropy production (called
reheating)

18. SOLVING

19. Inflation IImmpplleemmeenntteedd aass
SSccaallaarr--ffiieelldd DDyynnaammiiccss
Theorists:
When in
doubt, just
add a
scalar field

20. Solving the Flatness,
Horizon Problems

21. EEnnttrrooppyy
PPrroodduuccttiioonn//RReehheeaattiinngg
AAddiiaabbaattiicc:: CCoonnssttaanntt
NNuummbbeerr ooff PPhhoottoonnss ppeerr
ccoo--mmoovviinngg VVoolluummee,, ii..ee..,,
RRTT == ccoonnsstt

22. F Quantum Flluuccttuuaattiioonnss SSeeeedd
DDeennssiittyy PPeerrttuurrbbaattiioonnss

23. Homogeneous SSccaallaarr--ffiieelldd iiss
JJuusstt LLiikkee aa FFlluuiidd
≈ -1
• Slow roll (flat part of potential): w ≈ -1
• Rapid oscillation: particle production and
conversion of potential energy to particles
(heat) aka decay of φ particles

24. Given scalar
potential V(φ),
can compute
observables in
terms of V, V’
and V’’
• S = square of CMB
quadrupole due to
density perturbations
≈ 10-10
• T = square of CMB
quadrupole due to
density perturbations
≈ ??
• r = T/S

25. QQ:: WWhheerree ddiidd tthhee
aallmmoosstt ppeerrffeeccttllyy
ssmmooootthh hhoott qquuaarrkk
ssoouupp ccoommee ffrroomm??
AA:: DDeeccaayy ooff FFaallssee
VVaaccuuuumm EEnneerrggyy!!

26. QQ:: WWhheerree ddiidd tthhee
ssmmaallll lluummppss iinn tthhee
qquuaarrkk ssoouupp ccoommee
ffrroomm??
AA:: QQuuaannttuumm
FFlluuccttuuaattiioonnss!!

27. The Largest TThhiinnggss iinn tthhee UUnniivveerrssee
BBeeggaann ffrroomm SSuubbaattoommiicc QQuuaannttuumm
FFlluuccttuuaattiioonnss!!
WWOOWW!!

28. Quantum World PPrroojjeecctteedd AAccrroossss tthhee
SSkkyy bbyy tthhee EExxppaannssiioonn ooff tthhee UUnniivveerrssee
<< oonnee bbiilllliioonntthh tthhee ssiizzee
ooff aa pprroottoonn

29. Important FFaaccttss AAbboouutt IInnffllaattiioonn
1. Paradigm, no standard model, many
viable models (new, chaotic, …)
2. Key predictions
• Flat Universe: Ω0 = 1.000
• Almost scale-invariant adiabatic, almost
power-law, nearly Gaussian adiabatic
fluctuations
• |n-1| ~ O(0.1), |dn/dlnk| ~ O(10-3)
• Almost scale-invariant spectrum of
gravitational waves
• nT ~ 0 to -0.1 (i.e., negative)
3. Consistency relation: T/S = -5nT
• Unfortunately, T/S not directly related to n

30. IImmppoorrttaanntt FFaaccttss AAbboouutt
IInnffllaattiioonn,, ccoonntt’’dd
1. Measuring GWs immediately gives
scale of inflation!
1. But, no robust prediction for T/S (=r)
2. Inflationary perturbations + Cold
Dark Matter + “Λ” = ΛCDM scenario
for structure formation (another test)

31. T/S > 0.001 if n > 0.9?
Hoffman/Turner, PRD 64, 02350 (2001)

32. Important FFaaccttss AAbboouutt IInnffllaattiioonn,,
ccoonntt’’dd
7. Inflaton is described by a very
weakly coupled scalar field, weak
coupling makes reheating inefficient
1. Conditions for successful inflation
1. δρ/ρ ≈ 10-5 (hardest)
2. > 60 e-folds of inflation (easy)
3. Reheating to > 10 MeV (BBN), xx GeV
(baryogenesis)
4. No unwanted debris (e.g., gravitinos,
moduli fields, …)

33. Testing Inflation!
for almost 20 years an oxymoron

35. Michael S Turner
11999922:: CCOOBBEE
MMaappss &&
BBllaacckkBBooddyy
SSppeeccttrruumm

36. Michael S Turner
COBE Proves
Copernicus
Right!
WMAP uses this signal for
calibration

37. VSA ACBAR ACBAR
Michael S Turner
TOCO
BOOMERanG
DASI
CCMMBB EExxppeerriimmeennttss
Maxima
CBI
CBI

38. SPT
QUAD/BICEP/KECK
ACT
PolarBear
CAPMAP
CCMMBB EExxppeerriimmeennttss

39. Wilkinson MMiiccrroowwaavvee AAnniissoottrrooppyy
PPrroobbee ((WWMMAAPP))
±0.001% Michael Fluctuations
S Turner

40. Curve = concordance cosmology
Michael S Turner

41. SSeerriioouuss tteessttiinngg ooff
IInnffllaattiioonn hhaass bbeegguunn
KKeeyy PPrreeddiiccttiioonnss
• Flat Universe
• Almost scale-invariant, Gaussian perturbations:
|(n-1)| ~ 0.1 and |dn/dlnk| ~ 0.001
• Gravity waves: spectrum, but not amplitude
• Cold Dark Matter Scenario
KKeeyy RReessuullttss
• Ω0 = 1.0 ± 0.006
• (n-1) = -0.04 ± 0.014*; dn/dlnk = -0.032 ± 0.02; no
evidence for nonGaussianity
• r < 0.2 (95% cl)*
*Depends significantly upon the priors assumed

42. Michael S Turner
CCoolldd DDaarrkk MMaatttteerr
SScceennaarriioo
= Particle DM + Inflation
Structure Forms From the
Bottom Up:
First Stars (z ~ 10 -20)
Galaxies (z ~ 2 – 5), Clusters
(z ~ 0 - 2), and Superclusters
(z ~ 0)

43. Tracing the history from a slightly lumpy
Universe to galaxies ablaze
Michael S Turner

45. First significant
evidence for
inflation – still a
long road ahead
until it is “proven.’

46. IInnffllaattiioonn::
TThhee CChhaalllleennggeess AAhheeaadd
I. Observational – precision testing
II. Foundational – conceptual + laboratory
evidence

47. Precision TTeessttiinngg ooff IInnffllaattiioonn
• Measure and Ω0 to ±0.001 = 1.000?
• Measure n-1 to ±0.001 = ±O(0.1)?
• Detect dn/dlnk ±O(0.001)
• Gaussianity fNL ~ O(0.1)
• Detection of GW: T/S = ?
– CMB B mode polarization; or direct detection
• Measure nT T/S = -5nT?
– CMB B-mode or CMB + direct detection

48. • Successful Launch: 14 May 2009
• Coolest thing in space (100 mK)
• Ω0, n-1, dn/dlnk, Gaussianity, B-mode
polarization?
Michael S Turner

49. Coming Soon: Planck Surveyor Launch
2008 Cosmic Variance Limited to l ~ 2500
(vs WMAP to l ~ 1000) + polarization
Michael S Turner

50. GGWWss:: TThhee SSmmookkiinn’’ GGuunn
• Directly reveals epoch of inflation
• Reconstruct scalar potential
• Spectrum provides consistency check: T/S=-5nT
• Direct detection:
– LIGO & LISA unlikely; “Big Bang Observer” (a dream)
• B mode of CMB polarization

51. RReeccoonnssttrruuccttiioonn
small
T/S
large
T/S
small n-1 large n-1

52. E mode
B mode

53. CMB
Anisotropy
from Gravity
Waves
• ΘΘ = GW temp
• EE = E mode
(scalar)
• g lensing: grav
lensing of EE
• BB/g waves =
GW B-mode
• Detect T/S >
0.001?

54. Discovery of CMB
polarization:
DASI, 2002
Kovac et al, Nature 420, 772 (2002)

55. Polarization: Where we are today
Chiang et al, arXiv: 0906.1181
r = 0.1

56. CMBPol / Astro2010
Science Objectives for a Space Mission
8 yrs
1.2 yrs
4 yrs
CMB Community Reports
Probing Inflation with CMB Polarization, Baumann et al. 2008, ArXiv 0811.3919
Gravitational Lensing, Smith et al. 2008, ArXiv 0811.3916
Reionization Science with the CMB, Zaldarriaga et al. 2008, ArXiv 0811.3918
Prospects for Polarized Foreground Removal, Dunkley et al. 2008, ArXiv 0811.3915
Foreground Science Knowledge and Prospects, Fraisse et al. 2008, ArXiv 0811.3920

57. How Sub-Orbital Program Benefits a Satellite Mission
100 mK 1 mK 100 nK few nK
COBE
1989
Historical Interplay: Suborbital Experiments serve to
- Shape scientific objective of a space mission - Develop experimental methodologies
- Train leaders of future orbital missions - Develop technologies at systems level
CMBPol / Astro2010
WMAP
2001
Planck
2009
Sensitivity
60x
Sensitivity
20x
Sensitivity
>20x
CMBPOL
2022
Woody-Richards Archeops, Boomerang, Maxima
U2-DMR
QMAP, SK, TOCO
Sub-Orbital Precursor Satellite Mission
Multiple
Ground-based
&
Balloon-borne

58. FFoouunnddaattiioonnaall
• Fundamental theory of inflation: Who is φ?
– Many, many models, no compelling theory
– “Landau-Ginzburg” theory of inflation
• Laboratory test of inflation to close the circle
(e.g., produce a φ)
– Recall, “believe in BBN” because of laboratory
measurements (nuclei, nuclear physics cross
sections, etc)
– NB: dark matter is on the same path.

59. SShhoorrttccoommiinnggss ooff IInnffllaattiioonn

60. GGrreeaatt tthheeoorryy,, bbuutt ……
• No fundamental theory (still at Landau
Ginzburg stage – is there a BCS theory?)
• Does not address initial singularity
– geodesically incomplete
• Like “duct tape”, very useful but …
– Only postpones appearance of inhomogeneity
– not all initial conditions inflate
• Quantum unpredictability
• No laboratory signature/test

61. TTiimmee ttoo bbee bboolldd aaggaaiinn!!
some ideas
• Ekpyrotic (brane-collisions, s l o w
c o l l a p s e rather than rapid expansion
NB: solve horizon problem by d2a/dt2 and da/dt having same
sign, positive or negative
• Cyclic (multiple brane collisions)
• Variable speed of light??
• Pre big bang
No well developed competitor for inflation yet
Potential signatures: nonGaussianity, detection of
gravity waves (anti-signature)

62. SSuummmmaarryy
• Inflation addresses important shortcomings of the
standard model and has been the driving force in
cosmology for 3 decades
• First significant evidence for inflation (flat
Universe, nearly scale-invariant, Gaussian density
perturbations)
• Precision tests of inflation coming soon!
• GWs are smokin’ gun signature (but only
detectable if r > 0.001?)
• Foundational challenges: compelling model &
laboratory tests
• Time for a new bolder idea?

63. Time for Celebration
or a New Idea?
Time will tell
In any case
a most exciting time,
maybe even
a Golden Age
Michael S Turner
Theorists needed!

64. Question is now within
the realm of science
Three ideas – all probably
wrong!

65. neat & tidy!
… but Einstein’s
theory does not
incorporate
quantum
mechanics.
… and the
conditions at
the beginning
are precisely
where quantum
effects should
be critical!

66. Einstein got
the right
answer for
the wrong
reason!
= Emergence of
space and time

68. TTHHEE MMUULLTTIIVVEERRSSEE

69. IISS IITT SSCCIIEENNCCEE IIFF IITT I ISS NNOOTT TTEESSTTAABBLLEE??

70. WWee CCaann TTeesstt WWhheetthheerr oorr
NNoott ““OOuurr PPiieeccee ooff tthhee
MMuullttiivveerrssee”” OOrriiggiinnaatteedd
FFrroomm IInnffllaattiioonn
… well on our way to doing so

71. BRANE WWOORRLLDD OOFF SSTTRRIINNGG
TTHHEEOORRYY
WWEE LLIIVVEE OONN AA 33DD BBRRAANNEE IINN AANN 1111DD SSPPAACCEE
BBRRAANNEESS CCOOLLLLIIDDEE CCRREEAATTIINNGG BBIIGG BBAANNGGSS

73. Vacuum EEnneerrggyy PPrroobblleemm SSoollvveedd
bbyy SSuuppeerrssyymmmmeettrryy oorr ??

74. F Quantum Flluuccttuuaattiioonnss SSeeeedd
GGaallaaxxiieess aanndd CClluusstteerrss!!