The CMB and Neutrinos

We can all measure the CMB

TCMB=2.725 +\- 0.001 K

CMB approx 1% of TV noise!

400 photons/cc at 0.28 eV/cc

But no one has measured the neutrino background.

Neutrinos

Tn=1.945 K 3 known families, ~equal numbers of neutrinos and antineutrinos.

113 neutrinos/cc/family

When I say “neutrinos”….

0.05 eV<Smn<2.3 eV (95%cl)From atmospheric neutrinos at SuperK , nm nt

Tritium end point plus mass splittings. (Kraus et al., 2005)

From particle physics:

Neutrinos

Tn=1.945 K 3 known families, ~equal numbers of neutrinos and antineutrinos.

113 neutrinos/cc/family

0.05 eV<Smn<1.2 eV (95%cl)

WMAP aloneFrom atmospheric neutrinos at SuperK , nm nt

Neutrinos

Tn=1.945 K 3 known families, ~equal numbers of neutrinos and antineutrinos.

113 neutrinos/cc/family

0.05 eV<Smn<0.58 eV (95%cl)From atmospheric neutrinos at SuperK , nm nt

WMAP+BAO+H0

Neutrinos

Tn=1.945 K 3 known families, ~equal numbers of neutrinos and antineutrinos.

113 neutrinos/cc/family

0.05 eV<Smn<0.2 eV (95%cl)From atmospheric neutrinos at SuperK , nm nt

Expected from KATRIN (Franenkel, 2011)

Neutrinos

Tn=1.945 K 3 known families, ~equal numbers of neutrinos and antineutrinos.

113 neutrinos/cc/family

0.05 eV<Smn<0.06 eV (~95%cl)From atmospheric neutrinos at SuperK , nm nt

From Planck plus fine scale CMB polarization measurements (ACT, SPT….)

Cosmic Evolution

Us

Decoupling at z=1030

Decoupling surface

Cosmic Evolution

Cosmic Evolution

Cosmic Evolution

At decoupling

1972

WMAP at 61 GHz, 0.5 cm

The CMB at decoupling as seen through a Lambda-dominated spacetime (and through our galaxy).

Angular Power

Fundamental mode

rarefaction compression

“Acoustic peaks”

Model

compression

Spectrum

Silk damping tail

The Atacama Cosmology Telescope

~10X WMAP resolution

WMAP

148

GH

z21

8 G

Hz

277

GH

z

Pulse Tube

4He Fridge

3He Fridge

40K Shield

3K Shield

Window

1 m

DetectorsOptics

The Millimeter Bolometric Array Camera

Preliminary Power Spectrum

Silk damping tail

Number of relativistic species, NeffDunkley et al., 2011

The key to limiting Neff is to identify the increased damping at small angular scales in the CMB.

Silk damping tail

Hou et al., 2011Bashinsky & Seljak, 2004Jungman, Kamionkowski, Kosowsky, Spergel 1996

Neff

ACT+WMAP

ACT+WMAP+BAO+H0

Dunkley et al., 2011

WMAP

SPT+WMAP

SPT+WMAP+BAO+H0

Keisler et al., 2011

Komatsu et al., 2011

5.3 +/- 1.3

4.56 +/- 0.75

3.85 +/- 0.62

3.86 +/- 0.42

Compare today to that at decoupling. Greater relativistic means smaller rm/rr, enhanced potential evolution, and producing less cosmic structure.

Komatsu et al., 2009

e.g., Ichikawa et al., 2005

WMAP+BAO+SN, sum <0.58 (95%cl)

WMAP

Neutrino Mass #1

Neutrino Mass #2

Use the cosmic structure between us and the surface of last

scattering to lens the CMB, especially the small angles where

a massive neutrino inhibits the formation of structure.

Lensing is characteristically sensitive to mn

From Sudeep Das

Lensing smoothes out the peaks and alters the statistics of the CMB

Simulations

AAS, Jan 7 2010100 deg2

uK

AAS, Jan 7 2010

Simulations

100 deg2

uK

Lensing of CMB detected at 4s

Based on Hu & Okamoto estimator plus phase randomization.

Shape sensitive to neutrino mass.

And from SPT

van Engelen et al 2012

“Geometric Degeneracy”

CMB alone tells us we are on the “geometric degeneracy” line

closed

open

Assume flatness

WMAP7 only best fit LCDM

{Wbh2 = 0.0226 +/- 0.00057Wch2 = 0.1109 +/- 0.0056 h = 0.710 +/- 0.025 s8 = 0.801 +/- 0.030 t = 0.088 +/- 0.015 ns = 0.963 +/- 0.014

The Degeneracy

Sherwin et al. 2011

Lensing breaks the geometric degeneracy.

Lambda=0 excluded at 3.2 sigma from combination of WMAP and ACT.

Sherwin et al. 2011

Neutrino Mass #3

AAS, Jan 7 2010

Planck: sensitive to l=2000 in polarization

Can look through foregrounds in EE at l>2000.

Instruments & measurements underway by ACTPol, Polar, Polarbear, SPTPol.

Gravitational lensing turns E-modes into B-modes. Look for the effects of neutrinos in polarization.

Thank You