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Probing Inflation from

Cosmic Microwave Background

(CMB) Polarization

Masashi Hazumi

KEK

masashi.hazumi@kek.jp

New Experimental Cosmology Group at KEK

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CMB groupCMB group Formed in Dec. 2007Formed in Dec. 2007

Members: Members:

Masashi HazumiMasashi Hazumi

Masaya HasegawaMasaya Hasegawa

Takeo HiguchiTakeo Higuchi

Osamu TajimaOsamu Tajima

Takayuki Takayuki TomaruTomaru

Yuji Yuji ChinoneChinone (D1)(D1)

Future CMB satellite WGFormed in Sep. 2008

JAXA, KEK, NAOJ,

Berkeley, Caltech, Tohoku,

Okayama, RIKEN, Kinki

KEK Detector Technology Project

“Superconducting detector R&D”Formed in May 2007

KEK, RIKEN, Okayama, Tohoku

赤塚不二夫 著「ニャロメのおもしろ宇宙論」第10章素粒子で宇宙がわかるのだ

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Disclaimer

You are

theorists !

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Disclaimer

I’m an experimentalist.

My talk will not cover theoretical issues of

the inflationary universe.

You are

theorists.

Inflation

Hypothesis for “before the Big Bang”Hypothesis for “before the Big Bang”

Most promising, but incredibleMost promising, but incredible

Solves problems of flatness, horizons, Solves problems of flatness, horizons,

monopoles and structure formationmonopoles and structure formation

Accelerating expansion Accelerating expansion ““from an ameba to a from an ameba to a

galaxy in a fraction of a secondgalaxy in a fraction of a second””

example: 60 eexample: 60 e--fold expansion at t=10fold expansion at t=10--3636secsec

Beyond the Standard Model neededBeyond the Standard Model needed5

Scalar field and inflation

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Rmn – gmnR/2 = 8pGTmn

Einstein Eq.

example

Tmn = gmb(bf)(nf) – gm

n[gab (af)(bf/2) + V(f)]

Many scenarios assume

~1016 GeV

Inflation and primordial gravitational wave

(PGW)

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gmn =

-1 0 0 0

0

0 gij

0

Hij =

h+ h 0

h –h+ 0

0 0 0

Tensor perturbation

PGW

gij = a2(dij + Hij)

Scale factor

Kronecker delta

Inflation potential and T/S ratio

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r = T/S (tensor to scalar ratio)

There are scalar perturbations as well.

in case of

single-field

slow-roll inflation

See for example S. Weinberg “Cosmology” Sec.10.3 and references therein

PGW detection from

CMB polarization

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CMB Polarization1) Thomson scattering

CMB photons polarized

2) Perturbation in gmu

modifies the polarization

pattern.

“Polarization map” can be

obtained

Stokes parameters, E-mode, B-mode

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Ex, Ey: Complex electric fields

ExEy = (I0 + Q3 + U2 + V1)/2

Measure Linear polarization Q and U

i: Pauli matrices

I, Q, U, V: Stokes parameters

Polarization Map： Pab = Q(,f) U(,f)

U(,f) –Q(,f)

2PE abPab

2PB acacPab

PE: E-mode、Parity +

PB: B-mode、Parity -

CMB B-mode polarization

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E-modeB-mode

Scalar perturbationTensor perturbation

B-mode: Smoking gun signal of PGW

Comparison with laser interferometry

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“Task force on Cosmic Microwave Background Research”

(astro-ph/0604101)

The accurate measurement of CMB polarization is the The accurate measurement of CMB polarization is the

next critical step in extending our knowledge of both the next critical step in extending our knowledge of both the

early Universe and early Universe and fundamental physics at the highest fundamental physics at the highest

energiesenergies..

Detecting primordial gravitational waves would be one Detecting primordial gravitational waves would be one

of of the most significant scientific discoveries of all timethe most significant scientific discoveries of all time..

We recommend technology development leading to We recommend technology development leading to

receivers that contain a thousand or more polarization receivers that contain a thousand or more polarization

sensitive detectorssensitive detectors, , and adequate support for the and adequate support for the

facilities that produce these detectors.facilities that produce these detectors.

PGW detection:

from CMB temperature to polarization

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PGW imprinted in CMB BPGW imprinted in CMB B--mode polarizationmode polarization

The best way to discover PGWThe best way to discover PGW

Can determine inflation energy scale, end time of Can determine inflation energy scale, end time of

inflation, initial temperature of the Big Banginflation, initial temperature of the Big Bang

PGW

CMB polarization

B-mode

“curl component”

like magnetic field

CMB polarization map

Principles of

Measurements

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Observing system overview

CMB photons

optics

Receiver

system

cryostat

Cooling system

Focal plane Readout system

Control

system

Antenna

control

Recording

system

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Cf. CAPMAP receiver

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CAPMAP telescope

~30cm

polarimeter

Focal

plane90GHz 12 channels

40GHz 4 channels

Example of polarization detection scheme

2020

Det. Diode

L=EX+iEY R=EX-iEY

HEMT Amp.

Phaseswitch

4kHz

180 Coupler

90 Coupler

|LR|2+Q -Q

-U|LiR|2+U

+1 1

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CMB Polarization Power Spectra

W. Hu

et

al. a

stro

-ph

/0210096Temperature Anisotropy

Current

Required

inflation potential

r = T/S (tensor to scalar ratio is also the relative strength of PGW)

E mode measurements: status

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CAPMAP

11 observation

(Feb. 2008)

QUaD fit the E-mode

power spectrum !

(May 2008)

QUaD

20K HEMT amplifiers

0.3K bolometers

100GHz, 150GHz

40GHz, 90GHz

Activities of the KEK CMB Group

1.1. QUIET experimentQUIET experiment

2.2. QUIET+PolarBEARQUIET+PolarBEAR combined analysiscombined analysis

3.3. Future satellite mission “Future satellite mission “LiteBIRDLiteBIRD””

4.4. R&D on superconducting detectors R&D on superconducting detectors

(CMB camera)(CMB camera)

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QUIET: overview GroundGround--based experiment in Atacama (Chile)based experiment in Atacama (Chile)

Detector: HEMTDetector: HEMT

Innovative “polarimeters on a chip” (JPL)Innovative “polarimeters on a chip” (JPL)

Phase I commissioning: summer 2008Phase I commissioning: summer 2008

90 GHz “W90 GHz “W--band”: 91 elementsband”: 91 elements

40 GHz “Q40 GHz “Q--band”: 19 elementsband”: 19 elements

now taking data with Qnow taking data with Q--band modules !band modules !

Phase II: ~1000 elementsPhase II: ~1000 elements

Primary Mirror

2nd Mirror

Mount

Focal Plane

(Receiver)

Electronics

Box

Platelet

Array

Mirrors & Support Structure

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QUIET collaboration

BonnBonn TT modulesTT modules

CaltechCaltech beam, mount, softwarebeam, mount, software

ColumbiaColumbia cryostats, Qcryostats, Q--band arraysband arrays

JPLJPL Q/WQ/W--band modules, electronicsband modules, electronics

KEKKEK data stream managementdata stream management

KICP ChicagoKICP Chicago WW--band arrays, electronicsband arrays, electronics

KIPAC StanfordKIPAC Stanford telescopetelescope

ManchesterManchester telescopetelescope

MiamiMiami platelet arraysplatelet arrays

OsloOslo computingcomputing

OxfordOxford ground screenground screen

PrincetonPrinceton OMT, FPCOMT, FPC

also participating: Berkeley, Goddard, Harvard

47 members

as of Feb.08

QUIET receiver system

2626~40cm

Polarimeter on chip

Much smaller (1/10)

than before

Breakthrough for

Multi-channel

observation

Polarimeters on a chip (JPL)

2727

~3cm

W-band module

Det. Diode

L=EX+iEY R=EX-iEY

HEMT Amp.

Phaseswitch

4kHz

180 Coupler

90 Coupler

|LR|2+Q -Q

-U|LiR|2+U

+1 1

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Observing Life in Chile

Calama

How to get there ?

Example:

Japan – Chicago – Toronto

-Santiago – Calama

– San Pedro

~48 hours !San Pedro

QUIET

Sep.08 Tajima

Oct.08 Hasegawa

Nov.08 Hazumi

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Receiver

System

Cryostat

window

Primary Mirror

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2nd Mirror

Primary Mirror

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Receiver

System

CryostatElectronics

Box

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QUIET phase II (1000channels)

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KEK will play a significant role in the receiver system development,

the data acquisition system and analyses.

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QUIET: prospects

Expect to observe B-mode originating

from plausible inflation scenarios

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Verde-Peiris-Jimenez 2005

Pagano-Cooray-Melchiorri-Kamionkowski 2007

Point: QUIET+PolarBeaR combined analysis

will give the best sensitivity. Essential to have

evidence for r~0.01

QUIET PolarBeaRPolarBeaR+QUIET

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Expected sensitivities of future experiments

Point 2: Important to measure low l (down to reionization bump)

Need to go to space !

~20°

Point 1:

Impressive

sensitivities from

the ground

Magic patches

with small

foreground (OK

for l~100)

~2° ~0.2°

LiteBIRD

Small ! The entire satellite will be in a big cryochamber for testing.

175cm

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Future prospects

(LiteBIRD)

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Experimental Cosmology Program at KEK

Precision Measurements of Cosmic Microwave Background (CMB) Precision Measurements of Cosmic Microwave Background (CMB) PolarizationPolarization

Objective:: BB--mode polarization (“curl componentmode polarization (“curl component”)”)

Science:: Inflation, primordial gravitational wave, quantum Inflation, primordial gravitational wave, quantum gravitygravity

Projects: :

2007 08 09 10 11 12 13 14 15 16 17 18 19

QUIET

phase I phase II

QUIET+PolarBeaR

Combined analysis

Superconducting detector R&D

(w/ RIKEN etc.)

Satellite WG (w/ JAXA etc.)

Preparation for a (small) satellite

Launch before 2020

(Actual plans will depend on many factors)

PolarBeaR

Backup5151

Cosmology and Particle Physics

Cosmologytime

Big Bang

Inflation ?

1.371010yr(now)

10-36 sec？

PGW

? sec

3.8 105yr

1016？

Infla

ton

?

4 kinds of forces

En

erg

y (G

eV

)

Particle physics

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Theory of Everything ?

Accele

rato

r

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Lensing B-mode and neutrino mass

Side view

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Experimental sensitivity

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Total sensitivity

Rule of thumb

CMB photon density ~ 400/cm3

statistical fluctuation ~ 20/cm3

fundamental CMB photon noise ~ 60mK/sec

best detector available now ~ 200mK/sec/channel

“Ideal” detector: noise << CMB photon noise

Example: 1000ch. 1yr 60mK/ 10000.5 / (3107)0.5 ~ 0.35nK