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
WMAP
Planck
EPIC
TT
530(1)
1750(2)
3700
900(2)
2700
TE
EE
BB (lensing)
2600
1850
(1) Nolta et al. 2008
(2)
HFI, based on Planck Blue Book
Before EPIC-IM (2008): EPIC-LC and EPIC-CS
EPIC (LC) Low-Cost Option
Science
Science Requirements
Instrument
GW <BB>
Detect both l = 5 & l = 100 <BB> bumps at r = 0.01
after Galactic foreground removal
1º FWHM @100 GHz
All sky
2  Ks
2 years
30 – 300 GHz
EPIC (CS) Comprehensive Science Option
Science
Science Requirements
Instrument
GW <BB>
Detect both l = 5 & l = 100 <BB> bumps at r = 0.001
after Galactic foreground removal
5' FWHM @100 GHz
All sky
2  Ks
2 years
30 – 300 GHz
Lensing
<BB>
<EE>
Measure lensing <BB> to cosmic variance to l = 1000
Potential to subtract lensing <BB>
Measure <EE> to cosmic variance into the damping tail
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.
Inflationary
Parameters
Quantity
Discoverer
Amplitude of density
perturbations
COBE
Scalar spectral index
WMAP
Running of the spectral index
Planck?
Inflationary Gravitational
Waves
EPIC?
IGW spectral index
?
Running of the IGW index
?
Primordial non-Gaussianity
?
WMAP
Error with
Planck
Error with EPIC
32 +/- 21
5
2
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.
Lensed
Difference
Lensing studies
with EPIC
Foreground Mass
All Sky Maps of Projected Gravitational Potential
8º
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
11
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 decleaning?
~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 eV2
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 deg2, down to 7.5%)
When and how did the Universe
reionize?
Astrophysics
Measurement
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
Mission
Band
GHz
FWHM
arcmin
(Q)
kJy/sr/beam
Pol. depth
AV
Planck
350
5
24
4
500
2
0.9
0.06
850
1
0.7
0.01
EPIC-IM
21
How does large-scale Galactic field related
to field in embedded star-forming regions?
Summary