PLANCK
L’IMPATTO
SULLA
COSMOLOGIA
ALESSANDRO
MELCHIORRI
PLANCK@ROMA1
(Analisi Dati e Implicazioni Cosmologiche)
Paolo de Bernardis (Roma1)
Erminia Calabrese (Roma1) (PhD)
Silvia Masi (Roma1)
Alessandro Melchiorri (Roma1)
Luca Pagano (Roma1) (PhD)
Francesco Piacentini
Francesco De Bernardis (PhD)
Silvia Galli (PhD)
Giulia Gubitosi (PhD)
Matteo Martinelli (PhD)
Stefania Pandolfi (PhD)
Marcella Veneziani (ass. ric).
Laureandi Magistrale:
Maria Archidiacono
Paolo Fermani
Elena Giusarma
Andrea Maselli
Eloisa Menegoni
Marco Ruzza
…in collaborazione con
PLANCK@ROMA2
Grazia De Troia
Marina Migliaccio
Paolo Natoli
Nicola Vittorio
Giancarlo de Gasperis
….e altro
T  T 
1
 1   2  
T
T
2
 
 (2  1)C P  1   2 

Current status of CMB observations
We can measure cosmological parameters with CMB !
Temperature Angular spectrum varies with Wtot , Wb , Wc, L, t, h, ns, …
How to get a bound on a cosmological
parameter
Fiducial cosmological model:
(Ωbh2 , Ωmh2 , h , ns , τ, Σmν )
DATA
PARAMETER
ESTIMATES
Dunkley et al., 2008
Blu: Dati attuali
Rosso: Planck
F. De Bernardis, E. Calabrese, P. de Bernardis, S. Masi, AM 2009
Next experiment for measuring neutrino mass: KATRIN
 m  0.9eV
 m  6.6eV
Current limits from laboratory:
 m  6.6eV
Likelihood
Constraints on Newton’s constant
G/G0
G / G0  1.5%
S. Galli, A. Melchiorri, G. Smoot, O. Zahn, arxiv:0905.1808
CMB Temperature Lensing
unlensed
lensed
When the luminous source is the CMB, the lensing effect essentially
re-maps the temperature field according to :
Analysis Method
We phenomenologically uncoupled weak lensing from primary anisotropies
by introducing a new parameter AL that scales the lensing potential such as :
• AL=0 corresponds to a theory ignoring lensing
• AL=1 corresponds to the standard weak lensing scenario.
AL can also be seen like a fudge
parameter controlling the amount
of smoothing of the peaks. In fact
in this figure we can see that the
curves with increasingly smoothed
peak structures correspond to
analysis with increasingly values of
AL (0, 1, 3, 6, 9).
Future constraints
Planck
HFI 143 GHz Channel:
• fsky =1
• θ=7’
• NoiseVar=3,4·10-4 μK2
• fiducial model with ACBAR+WMAP3 best fit
parameters
Letting the lensing parameter vary, the obtained constraints are:
E. Calabrese, A. Slosar, A. Melchiorri, G. Smoot, O. Zahn, PRD, 2008
Calabrese, Martinelli, AM, Pagano, 2009
CMB POLARIZATION
Fluctuation and GW
generator
Fluctuation amplifier
But GW dissipator…
On this map we see 100000 horizons at z=1000….
d hor  ct
at   t 2 / 3
T  T 
 1   2   1
T
T
2
 

(
2


1
)
C
P


  1  2 

SCALAR
+
TENSOR
=
We measure the
sum of the two spectra.
If GW are present this
lowers the amplitude
of the peak.
Degeneracy with other
Parameters.
AT
r
AS @ k 0.017Mpc1k
CMB Polarization
• Polarization is described by Stokes-Q and -U
• These are coordinate dependent
• The two dimensional field is described by a gradient of a scalar (E)
or curl of a pseudo-scale (B).
ˆ
Temperature map : T(n )
Polarization map : P(nˆ )  E    B
Grad (or E) modes
Curl (or B) modes
(density fluctuations have no
handness, so no contribution
to B-modes). B-Modes=Gravity
Waves !!
Several inflationary
models predict
a sizable GW background
(r>0.01) if n<1.
Pagano, Cooray, Melchiorri
And Kamionkowsky, JCAP 08.