Transcript Asantha Cooray, Lessons from US CMBPol: theoretical considerations
Experimental Probe of Inflationary Cosmology
(comparison of three EPIC versions)
Asantha Cooray University of California-Irvine
Post-Planck Mission Effort in US
Deliverables
The ell to which measurements are cosmic variance limited Observable TT TE EE BB (lensing) WMAP 530 (1) Planck 1750 (2) 900 (2) EPIC 3700 2700 2600 1850 (1) Nolta et al. 2008 (2) HFI, based on Planck Blue Book
Before EPIC-IM (2008): EPIC-LC and EPIC-CS
Science GW
EPIC (LC) Low-Cost Option
Science Requirements Detect
both
l = 5 & l = 100
r = 0.01
after Galactic foreground removal
Instrument 1º FWHM @100 GHz All sky 2 K s 2 years 30 – 300 GHz Science GW
EPIC (CS) Comprehensive Science Option
Science Requirements Detect
both
l = 5 & l = 100
r = 0.001
after Galactic foreground removal
Measure lensing
Potential to subtract lensing
Instrument 5' FWHM @100 GHz All sky 2 K s 2 years 30 – 300 GHz Measure
Phase I: Two mission options
EPIC-IM (2008/2009 version)
EPIC=EPIC IM EPIC CS = Cosmic variance
Last word on the “Age question” Our final age determination will be accurate to 25 Myrs.
This is enabled by the cosmic variance limited E-mode measurement.
Quantity Amplitude of density perturbations Scalar spectral index Running of the spectral index Inflationary Gravitational Waves IGW spectral index Running of the IGW index Primordial non-Gaussianity
Inflationary Parameters
Discoverer COBE WMAP Planck?
EPIC?
?
?
?
WMAP 32 +/- 21 Error with Planck Error with EPIC 5 Amplitude of the inflationary gravitational waves depends only on the energy scale of inflation. Interpretation is NOT model-dependent.
The information captured by the inflationary gravitational wave background is unique, it cannot be obtained even with a perfect measurement of the scalar spectral index and its running.
2
Lensed Lensing studies with EPIC Lensed Difference Foreground Mass
All Sky Maps of Projected Gravitational Potential 8
º Theoretical projected potential Optimal Quadratic
(Hu 2001)
Likelihood
(Hirata & Seljak 2003)
Gravitational potential determined from CMB polarization and temperature maps sensitive to
- neutrino masses - dark energy
All-sky potential map: maps to cosmic limits on the whole sky!
- a legacy for every future study of structure formation
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Measuring the lensing power spectrum NET muK/sqrt(sec) one-year
Lensing Removal and the Search for Gravitational-wave B-modes
What is the optimal resolution for lens de cleaning?
~4 arcmins is the ideal beam size Scientific Gain = (T/S-limit with lens cleaning)/(without cleaning)
Particle physics application of EPIC CMB lensing probes linear fluctuations Source properties known
(Both these lead to systematic errors in galaxy lensing)
Lensing B-modes and CMB Cosmic Shear Reconstruction neutrino mass (
m
< 0.05 eV; from the linear regime)
Test SuperK Atmosphere oscillations that suggest
m
2
2x10 -3 eV 2 and distinguish between two mass hierarchies
What is the neutrino mass hierarchy?
EPIC can not only measure the total sum of neutrino masses, but when combined with atmospheric oscillation result for the mass-squared difference, establish individual masses of all three neutrino species.
Better than (<) 6 arcmin resolution is a requirement for EPIC to enable CMB lensing studies.
The measurement cannot be achieved with a lensing analysis in a small patch of the sky. All-sky coverage is essential.
Did dark energy exist at z> 2?
In some models of dark energy, a small contribution exist to the total energy density budget of the Universe at z >2.
CMB lensing probes cosmology at z of 2 to 4, where the lensing efficiency is highest.
EPIC can constrain the early dark energy density to better than 0.1%.
(Half-sky weak lensing with planned Euclid can only constrain same down to 2.5%.
JDEM with 4000 deg 2 , down to 7.5%)
When and how did the Universe reionize?
Reionization history
Model-dependent constraints
Reionization history
Model-independent constraints EPIC allows cosmic variance extraction of 5 components.
Mapping Galactic Magnetic Fields over the Whole Sky
Map of full sky with P < 0.3 % Planck EPIC-IM 21
Mission
Planck EPIC-IM
Band GHz
350 500 850
FWHM arcmin
5 2 1
(Q) kJy/sr/beam
24 0.9
0.7
Pol. depth A V
4 0.06
0.01
How does large-scale Galactic field related to field in embedded star-forming regions?