Theoretical Cosmology and Particle Astrophysics at Caltech

1
Theoretical Cosmology and Particle Astrophysics
at Caltech

• Marc Kamionkowski
• August 10, 2005

2
Astronomy/Astrophysics at Caltech
3
Also, SIRTF, GALEX, Hershel..... and everything
at JPL. And Carnegie Observatories down the
road....
4
Caltech/JPL will be US center for experimental
early-Universe cosmology over next decade

• Caltech faculty Readhead, Lange, Zmuidzinas,
  Golwala
• Boomerang was first experiment to map acoustic
  peaks in CMB
• CBI was first to measure power on smaller scales
• Have vigorous ongoing ground/balloon-based
  programs (BICEP, QUaD, QUIET, B2K, CBI, ACBAR,
  JAKNIFE.)
• Are US PI institution for Planck LFI and HFI, and
  will have US Planck data analysis center

5
Theoretical Astrophysics and
Relativity Thorne, Sari, Phinney, Goldreich
(part) stellar astrophysics, relativity,
gravitational waves, cosmology,
high-energy astrophysics.... Strong postdoc
program (Narayan, Tremaine, Bildsten,
Hogan....)
6
Cosmology/ Û Particle/Nuclear Astrophysics
Physics

• Dark matter
• Dark energy
• Inflation
• Neutrino astrophysics
• Ultrahigh-energy cosmic rays
• Baryogenesis

7
People now (at least loosely) affiliated with
Caltech theoretical cosmology and particle
astrophysics

• Postdocs/SRFs
• Asantha Cooray (Sherman Fairchild Senior Research
  Fellow DoE research expenses)
• Milos Milosavljevic (Fairchild Fellow)
• Steven Furlanetto (DuBridge Fellow 20 Task B
• L. Arielle Phillips (Irvine Fellow)
• Nicole Bell (Fairchild Fellow)
• James Taylor (supported by R. Ellis)
• Stefano Profumo (arrives this fall 60 Task B)

8
People now (at least loosely) affiliated with
Caltech theoretical cosmology and particle
astrophysics

• Graduate Students
• Mike Kesden (NASA GSRP -gt CITA)
• Nevin Weinberg (NASA ATP -gt KITP, Berkeley)
• Kris Sigurdson (NSERC/DoE-gt IAS/Hubble Fellow)
• Jonathon Pritchard (TA/DoE)
• Tristan Smith (NSF Fellow)
• Anthony Pullen (NSF Fellow)
• Adrienne Erickcek (NSF Fellow)
• Dan Grin (Moore Fellow)

9
People now (at least loosely) affiliated with
Caltech theoretical cosmology and particle
astrophysics

• Other Researchers
• Kris Gorski (JPL Visiting associate)
• Elena Pierpaoli (senior research fellow supported
  by NSF ADVANCE fellowship)
• Andrew Benson (Moore SRF to arrive spring 2006)

• Visitors
• Robert Caldwell (will visit this fall from
  Dartmouth)
• Tsvi Piran (Moore distinguished scholar 2004-5)

10
Some Recent Alumni

• Students
• Mike Santos (PhD 2003 now postdoc at Cambridge)
• Catherine Cress (PhD 1999 (Columbia) Natal
  faculty)
• Alexandre Refregier (PhD 1998 (Columbia) CNRS
  faculty)
• Xuelei Chen (PhD 1999 (Columbia) KITP postdoc)

• Postdocs
• Piero Ullio (1999-2000 SISSA faculty)
• Ken Nollett (2000-2002 permanent member, Argonne
  nuclear theory group)
• Peng Oh (2000-2003 UCSB faculty)
• Andrew Benson (2000-2003 Roy Soc advanced
  fellow)
• Eric Agol (2000-2003 Washington faculty)

11
Caltech is building in particle astrophysics

• Experiment
• Added Sunil Golwala (dark matter, dark energy,
  CMB) to faculty 2003

• Theory
• Are searching for junior theorist

Heart of Darkness initiative will seek private
funding for theoretical activity at
string/particle/cosmology interface
12
Our recent (year) research topics

• Effects of dark-matter dipole moments, decays
• Variable fine-structure constant
• Probes of dark matter at Galactic center
• Dark energy, phantom energy, Big Rip
• Galactic-halo merger rates
• CMB tests of inflation
• Cooling problem in galaxy clusters
• Intergalactic medium
• Supersymmetric dark matter
• Large-scale structure, weak lensing, inflation,
  and dark energy
• The first stars and reionization
• 100 refereed publications over past 5 years

13
Our work is relevant for

• SNAP/JDEM
• CMB experiments (WMAP, Planck, CMBPOL
• GLAST/VERITAS/STACEE/.
• Collider experiments (to some extent)
• Neutrino experiments
• CDMS, etc.
• Super-K, IceCube.
• LSST
• SDSS/2dF.
• AMS.

14
Benefits of this program to DoE

• DoE funding heavily leveraged by Caltech
• Maintains theoretical activity at major center
  for experimental particle astrophysics and
  early-Universe cosmology
• Supports training of some of the best postdocs
  and students in the field
• Grad student support goes only to students in
  final year of research, when they are most
  productive
• One-professor budget supports theory program in
  exciting emerging area that competes with
  programs with larger faculty numbers

15
Funding profile

• 1999-2003 100K/year (PI summer salary plus
  student)
• 2003-2004 150K/year (PI summer salary,
  student, plus 2nd student or 50 postdoc)
• 2004-2005 140K/year
• Current request continued funding at current
  level
• Eventually, would like to be able to support 100
  postdoc plus student from this Task.

16
Journal articles completed over past 12 months
under Task B
Pair Correlations and Merger Bias, Steven R.
Furlanetto and Marc Kamionkowski,
astro-ph/0507650. Dynamical Friction and
Cooling Flows in Galaxy Clusters, Woong-Tae
Kim, Amr El-Zant, and Marc Kamionkowski,
astro-ph/0506579. Direct Detection of the
Inflationary Gravitational-Wave Background,
Tristan L. Smith, Marc Kamionkowski, and Asantha
Cooray, astro-ph/0506422 A Running
Spectral Index in Supersymmetric Dark-Matter
Models with Quasi-Stable Charged Particles,''
Stefano Profumo, Kris Sigurdson, Piero Ullio,
and Marc Kamionkowski, Phys. Rev. D 71,
023518 (2005).
17
Highly-Ionized Oxygen Absorbers in the
Intergalactic Medium,'' Steven R. Furlanetto, L.
Arielle Phillips, and Marc Kamionkowski,
MNRAS 359, 295--307 (2005). Cosmic
Microwave Background Fluctuations from
Gravitational Waves An Analytic Approach,''
Jonathon R. Pritchard and Marc Kamionkowski,
Ann. Phys. 318, 2 (2005). Cosmic Shear
of the Microwave Background The Curl
Diagnostic,'' Asantha Cooray, Marc Kamionkowski,
and Robert R. Caldwell, Phys. Rev. D 71,
123527 (2005). The Kinetic Sunyaev-Zel'dovich
Effect from Reionization'' Matthew McQuinn,
Steven R. Furlanetto, Lars Hernquist, Oliver
Zahn, and Matias Zaldarriaga,
astro-ph/0504189. Submitted to ApJ. Is Double
Reionization Physically Plausible?'' Steven
R. Furlanetto and Abraham Loeb,
astro-ph/0409656.
18
Polarization Signals of the 21 cm Background
from the Era of Reionization'' Asantha Cooray
and Steven R. Furlanetto, MNRAS 359, L47
(2005). Ly-alpha Emission from Structure
Formation'' Steven R. Furlanetto, Joop
Schaye, Volker Springel, and Lars Hernquist,
ApJ 622, 7 (2005). How Universal is the
Gunn-Peterson Trough at z6? A Closer Look
at the Quasar SDSS J11485251'' S. Peng Oh
and Steven R. Furlanetto, ApJL 620, L9
(2005). The Temperature Structure of the
Warm-Hot Intergalactic Medium'' Naoki
Yoshida, Steven R. Furlanetto, and Lars
Hernquist, ApJL 619, L91 (2005). Constraining
the Topology of Reionization Through
Ly-alpha Absorption'' Steven R. Furlanetto,
Lars Hernquist, and Matias Zaldarriaga,
MNRAS 354, 695 (2004).
19
What is L? Anatomy of the Galaxy Luminosity
Function,'' Asantha Cooray and Milos
Milosavljevic, astro-ph/0504580. An
indirect limit on the amplitude of primordial
Gravitational Wave Background from CMB-Galaxy
Cross Correlation,'' Asantha Cooray, P. S.
Corasaniti, T. Giannantonio, and A.
Melchiorri, astro-ph/0504290. Dissipationless
Merging and the Assembly of Central
Galaxies,'' Asantha Cooray and Milos
Milosavljevic, astro-ph/0503596. Cosmic 21-cm
Delensing of Microwave Background
Polarization and the Minimum Detectable Energy
Scale of Inflation,'' Kris Sigurdson and
Asantha Cooray, astro-ph/0502549. Submitted
to Phys. Rev. Lett. Can LISA Resolve Distance
to the Large Magellanic Cloud?'' Asantha
Cooray and Naoki Seto, Astrophys.J 623,
L113--L116 (2005).
20
Cosmological Constraints on the Very Low
Frequency Gravitational-Wave Background
Authors,'' Naoki Seto and Asantha Cooray,
astro-ph/0502054. Large-Scale
Non-Gaussianities in the 21 cm Background
Anisotropies From the Era of Reionization,''
Asantha Cooray, astro-ph/0411430. Multifrequen
cy analysis of 21 cm fluctuations from the
Era of Reionization,'' Mario G. Santos,
Asantha Cooray and Lloyd Knox,''
astro-ph/0408515. Gravitational Wave
Background of Neutron Star-White Dwarf
Binaries,'' Asantha Cooray, MNRAS 354,
25--30 (2004). Cross-Correlation Studies
between CMB Temperature Anisotropies and 21
cm Fluctuations,'' Asantha Cooray, Phys.
Rev. D 70, 063509 (2004). Search for
Small-Mass Black Hole Dark Matter with
Space-Based Gravitational Wave Detectors,''
Naoki Seto and Asantha Cooray, Phys. Rev. D
70, 063512 (2004).
21
First Sources in Infrared Light Stars,
Supernovae and Miniquasars,'' Asantha Cooray and
Naoki Yoshida, MNRAS 351, L71--L77
(2004). Uncorrelated Estimates of Dark Energy
Evolution,'' Dragan Huterer and Asantha
Cooray Phys. Rev. D 7, 023506 (2005).
22
Inflationary Gravitational Waves, CMB
Polarization, and Direct Detection
23
NASA COBE map of CMB temperature (1991-1994)
24
BOOMERanG map of CMB (2000)
25
Pre-WMAP bolometer-based measurements BOOMERanG,
ARCHEOPS, ACBAR
26
BOOMERanG (2002)
Universe is flat structure grows from primordial
adiabatic perturbations
27
STRUCTURE FORMATION
GEOMETRY
SMOOTHNESS
INFLATION
28
WHAT NEXT???
29
Caldwell, MK, Wadley
30
(from H. C. Chiang)
History of the universe (to scale!)
electron-positron annihilation t 5 sec
reionization t 0.2 gyr
dark matter decoupling t 1e-10 sec
BBN t 3 min
neutrino decoupling t 1 sec
matter-lambda equality t 9.5 gyr
matter-rad. equality t 56 kyr
EW symmetry breaking t 1e-12 sec
here be dragons
quark-hadron transition t 1e-5 sec
formation of CMB t 400 kyr
end of inflation t 1e-35 sec
you are here t 13.7 gyr
EM opaque
Transparent to GWs
31
STRUCTURE FORMATION
GEOMETRY
SMOOTHNESS
INFLATION
What is Einfl?
STOCHASTIC GRAVITATIONAL WAVE BACKGROUND with
amplitude ?Einfl2
32
Detection of gravitational waves with CMB
polarization
(MK, Kosowsky, Stebbins, 1996 Seljak
Zaldarriaga 1996)
Temperature map
Polarization Map
Density perturbations have no handedness so they
cannot produce a polarization with a curl
Gravitational waves do have a handedness, so
they can (and do) produce a curl
Model-independent probe of gravitational waves!
33
No Gravity Waves
34
Gravity Waves
35
Direct Detection of Inflationary Gravitational
Waves?(T. L. Smith, MK, Cooray, astro-ph/0506422)

• Mission concept studies
• NASA Big-Bang Observer (BBO)
• Japan Deci-Hertz Gravitational-Wave
  Observatory (DECIGO)
• seek to detect directly inflationary
  gravitational-wave background at 0.1-Hz
  frequencies

36
(No Transcript)
37
Survey some toy models for inflation
power-law
chaotic
hybrid
symmetry-breaking
38
Tensor-to-scalar ratio r
39
chaotic
Power-law
Symmetry breaking
chaotic
40
Other possibilities?

• Phantom energy (wlt-1) driven inflation (Baldi,
  Finelli, Matarrese 2005)
• Pre-big-bang, cyclic, and ekpyrotic models
• may produce blue GW spectra larger direct
  signal, without increasing CMB signal

41
Conclusions

• IGWB is detectable in many inflation models
• IGWB probably not directly detectable if does not
  show up in CMB polarization
• Large lever arm between CMB and BBO/DECIGO scales
  provides unique probe of inflationary models