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Seeing the Earliest Photons: the CMB from Bell Labs to Planck - - PowerPoint PPT Presentation

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Seeing the Earliest Photons: the CMB from Bell Labs to Planck Andrew Jaffe Courtesy Charles Lawrence TAUP 2009 1 July Thursday, 9 July 2009 Seeing the Earliest Photons: the CMB from Bell Labs to Planck The history and physics of the CMB

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SLIDE 1

Seeing the Earliest Photons: the CMB from Bell Labs to Planck

Andrew Jaffe TAUP 2009 1 July

Courtesy Charles Lawrence

Thursday, 9 July 2009

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SLIDE 2

Seeing the Earliest Photons: the CMB from Bell Labs to Planck

□ The history and physics of the CMB □ Primordial fluctuations □ Observing the fluctuations

■ from space — COBE, WMAP ■ and earth — Boomerang, MAXIMA, ...

□ A standard cosmological model? □ Or important anomalies? □ Next: Planck, EBEX, Polarbear

Thursday, 9 July 2009

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SLIDE 3

The First Picture of the CMB

  • Penzias & Wilson, 1965

Thursday, 9 July 2009

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SLIDE 4

The First Picture of the CMB

  • Penzias & Wilson, 1965

Thursday, 9 July 2009

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SLIDE 5

Black Body radiation from the Early Universe

Mather et al, 1994

Penzias & Wilson

Thursday, 9 July 2009

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SLIDE 6

Black Body radiation from the Early Universe

Mather et al, 1994

Penzias & Wilson

Thursday, 9 July 2009

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SLIDE 7

Black Body radiation from the Early Universe

Al Kogut, ARCADE, http://arcade.gsfc.nasa.gov/cmb_spectrum.html

Thursday, 9 July 2009

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SLIDE 8

History

■ 1948: Alpher, Gamow, Herman predict the existence of

the CMB

■ 1964: Dicke, Peebles, Roll & Wilkinson (Princeton) start

looking

■ 1964: Penzias & Wilson (AT&T Bell Labs) accidently find

it

□

T = 3K, constant over sky

■ 1969-70s: 0.1% variations

□

Doppler Shift from our motion through the CMB

■ 1990s: 10-5 variations

□

Sign of the large-scale structure of the universe at early times

Thursday, 9 July 2009

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SLIDE 9

The Cosmic Microwave Background

□ 400,000 years after the Big Bang, the temperature

  • f the Universe was T~10,000 K

□ Hot enough to keep hydrogen atoms ionized until

this time

□ proton + electron → Hydrogen + photon [p+ + e- → H+γ] □ charged plasma → neutral gas

□ Photons (light) can't travel far in the presence of

charged particles

□ Opaque → transparent

  • W. Hu

Thursday, 9 July 2009

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SLIDE 10

Cosmological Horizons

 Physics works at the speed of light:  No “causal influence” from more than

  • Horizon distance

dH = (age of universe) × (speed of light)

  • [Sound] horizon at LSS ~1°
  • In the standard big bang, the horizon always grows
  • But here’s what Penzias & Wilson saw:
  • T = 3K, ~constant over sky

How did everything get to be the same temperature????

Oscillations in primordial plasma (sound waves)

Thursday, 9 July 2009

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SLIDE 11

Inflation

□ Expand the universe by a

factor >>1030 at t~10-30 sec.

■ a∝eHt

□ Makes the universe flat (Ω=1) □ Puts it all into “causal contact”

(so the CMB can be isotropic)

□ Generates perturbations that

become galaxies, clusters, etc.

■ QM perturbations in primordial fields ■ scalar — density perturbations ■ tensor — gravitational radiation □ But: no way yet to choose

among specific models within particle physics, string theory, relativity

Thursday, 9 July 2009

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SLIDE 12

□

Initial temperature (density) of the photons

□

Doppler shift due to movement of baryon-photon plasma

□

Gravitational red/blue-shift as photons climb out of potential wells or fall off of underdensities

□

Photon path from LSS to today

□

All linked by initial conditions ⇒ 10-5 fluctuations

What affects the CMB temperature?

Cooler Hotter

Thursday, 9 July 2009

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SLIDE 13

□

Initial temperature (density) of the photons

□

Doppler shift due to movement of baryon-photon plasma

□

Gravitational red/blue-shift as photons climb out of potential wells or fall off of underdensities

□

Photon path from LSS to today

□

All linked by initial conditions ⇒ 10-5 fluctuations

What affects the CMB temperature?

Cooler Hotter

Thursday, 9 July 2009

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SLIDE 14

□

Initial temperature (density) of the photons

□

Doppler shift due to movement of baryon-photon plasma

□

Gravitational red/blue-shift as photons climb out of potential wells or fall off of underdensities

□

Photon path from LSS to today

□

All linked by initial conditions ⇒ 10-5 fluctuations

What affects the CMB temperature?

Cooler Hotter

Thursday, 9 July 2009

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SLIDE 15

□

Initial temperature (density) of the photons

□

Doppler shift due to movement of baryon-photon plasma

□

Gravitational red/blue-shift as photons climb out of potential wells or fall off of underdensities

□

Photon path from LSS to today

□

All linked by initial conditions ⇒ 10-5 fluctuations

What affects the CMB temperature?

Cooler Hotter

Thursday, 9 July 2009

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SLIDE 16

Fluctuations in the CMB

Inflation???

Thursday, 9 July 2009

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SLIDE 17

Describing the (CMB) Universe

□ Allows us to define the power spectrum, Cl

■ Assumes isotropy (no absolute orientation) ■ If we also assume Gaussianity (e.g., inflation):

T(ˆ x) − ¯ T ¯ T ≡ ∆T T (ˆ x) =

  • ℓm

aℓmYℓm(ˆ x) a∗

ℓmaℓ′m′ = δℓℓ′δmm′ Cℓ

“Fourier transform”

  • n a sphere

P(aℓm|Cℓ) = 1 √2πCℓ exp

  • −1

2 |aℓm|2 Cℓ

  • Thursday, 9 July 2009
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SLIDE 18

Theoretical Predictions

~180°/Angular scale Mean square fluctuation amplitude

Thursday, 9 July 2009

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SLIDE 19

CMB Anisotropy Experiments

■ 1989-1993: COBE/DMR (NASA)

■ Full-sky, 7° beam (much larger than ~1° horizon)

■ Early 1990s: Small-scale Experiments

■ balloon & ground-based, ~1° beam

1990s-2000s: 2nd generation

MAXIMA/BOOMERANG, DASI/CBI, VSA, Archeops, ACBAR, QUaD

■ 2003+: WMAP (NASA): New Results

■ May 2009++: Planck Surveyor (ESA)

■ 2000-10s: 3rd generation experiments (B-Modes)

■ SPIDER, Polarbear, EBEX, Clover

Thursday, 9 July 2009

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SLIDE 20

January, 2003

Thursday, 9 July 2009

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SLIDE 21

WMAP!

Thursday, 9 July 2009

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SLIDE 22

Measuring Curvature with the CMB

Flat Us! Last Scattering Surface Ω=1

Thursday, 9 July 2009

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SLIDE 23

Closed Ω>1 Us! Last Scattering Surface

Measuring Curvature with the CMB

Thursday, 9 July 2009

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SLIDE 24

Open Us! Last Scattering Surface Ω<1

Measuring Curvature with the CMB

Thursday, 9 July 2009

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SLIDE 25

Thursday, 9 July 2009

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SLIDE 26

WMAP's orbit

Thursday, 9 July 2009

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SLIDE 27

WMAP and other data

Thursday, 9 July 2009

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SLIDE 28

WMAP and other data

Thursday, 9 July 2009

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SLIDE 29

Maps of the Cosmos

DMR WMAP MAXIMA

Thursday, 9 July 2009

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SLIDE 30

Measuring the geometry of the Universe

Amount of “matter” (normal + dark) Amount of “dark energy” (cosmological constant)

Flat Universe Ωtot=Ωm+ ΩΛΛ=1

WMAP

Thursday, 9 July 2009

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SLIDE 31

Temperature and polarization from WMAP

Thursday, 9 July 2009

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SLIDE 32

The Polarization of the CMB

  • Anisotropic radiation field at last

scattering → polarization

  • “Grad” or E mode
  • Breaks degeneracies
  • New parameters:
  • reionization
  • “Curl” or B sensitive to

gravity waves

  • “Smoking gun” of inflation?
  • Very low amplitude
  • Need better handle on

systematics, and...

  • Polarized foregrounds?

Temperature

(determined by params)

E-Mode Pol

(determined by params)

B-Mode Pol

(depends on inflation)

  • DASI
  • MAXIPOL, B2K
  • MAP
  • Planck
  • Future satellites?

E E B B

Thursday, 9 July 2009

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SLIDE 33

Temperature

Temperature/ E-Polarization E-Polarization

B- Polarization

Thursday, 9 July 2009

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SLIDE 34

CMB Measurements: State of the Art

Chiang et al 2009

Thursday, 9 July 2009

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SLIDE 35

The “unified” spectrum c. 2008

Contaldi & Jaffe

Thursday, 9 July 2009

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SLIDE 36

A “Standard Cosmological Model” from the CMB?

□ Largely confirms results from COBE,

MAXIMA, BOOMERANG, etc.

■ Flat Universe (Ω=1)

□

23% Dark Matter

□

4% Normal Matter

□

73% “Dark Energy” (accelerating the expansion)

■ Initial seeds consistent w/ Inflation ■ Hubble constant 72 km/s/Mpc

□ Details depend on “priors” (irrevocably: feature, not bug…)

Thursday, 9 July 2009

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SLIDE 37

Anisotropy (from topology?)

□ Low power at large scales? □ Problem becomes more acute

beyond the power spectrum

□ Multi-connected topology?

□ Finite universe

■ Cutoff at large scales induces

power deficit

■ In closed universe cutoff

determined by curvature alone

□ Intrinsic anisotropy (orientable manifolds)

■ Possible apparent non-Gaussianity

□ Effects only present at large scales – at smaller scales standard

ΛCDM power spectrum recovered

□ (Luminet et al “Soccer Ball” [Dodecahedron/Poincaré] universe?)

Thursday, 9 July 2009

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SLIDE 38

Anisotropy (from topology?)

□ Low power at large scales? □ Problem becomes more acute

beyond the power spectrum

□ Multi-connected topology?

□ Finite universe

■ Cutoff at large scales induces

power deficit

■ In closed universe cutoff

determined by curvature alone

□ Intrinsic anisotropy (orientable manifolds)

■ Possible apparent non-Gaussianity

□ Effects only present at large scales – at smaller scales standard

ΛCDM power spectrum recovered

□ (Luminet et al “Soccer Ball” [Dodecahedron/Poincaré] universe?)

Thursday, 9 July 2009

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SLIDE 39

Topology in a flat “universe”

Don’t need to “embed” the square to have a connected topology. “tiling the plane”

Thursday, 9 July 2009

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SLIDE 40

Topology + geometry

□ Tile the 2-sphere with different fundamental domains

□ Harder to visualize in 3-d:

Thursday, 9 July 2009

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SLIDE 41

Model Comparison

 WMAP 3-yr data

  • significant diffs from 1yr, e.g.,
  • ctupole
  • First-year low power favors

“small” fundamental domain to lower quadrupole (smooth low-l “decay”)

 Details depend on “priors”:

  • esp. H0 for Cℓ odds
  • This is a topology-specific test (cf.

“circles-in-the-sky” which purports to be more generic)

  • Difficult (impossible?) to test when

(topology scale)>>(Hubble scale)

Model

Odds: Cℓ alone Odds: Cℓmℓ’m’

Simply- connected

1 1

Quaternionic

0.07 0.04

Octahedral

0.32 0.005

Truncated Cube 0.14

0.0003

Poincaré

0.04 ≪1

Thursday, 9 July 2009

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SLIDE 42

really exotic physics

□ Parity violation in the early universe

■ helicity induces EB, TB correllations ■ (Kahniashvili; Alexander)

□ holography: information quantization (Hogan)

■ discrete spacetime ■ AdS-CFT correspondence and information bounds ■ 10120 bits in observable Universe back to Planck epoch

□ inflation could reduce this to 1010!!

Thursday, 9 July 2009

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SLIDE 43

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SLIDE 44

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SLIDE 45

Future (soon) spectra

Planck gets ~all of T, most of E Wide frequency coverage for

“foreground” removal

Breaks “conceptual” degeneracies (do

we have the overall model correct?); most parameters better determined by factor of ~few.

Thursday, 9 July 2009

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SLIDE 46

Future (soon) spectra

Planck gets ~all of T, most of E Wide frequency coverage for

“foreground” removal

Breaks “conceptual” degeneracies (do

we have the overall model correct?); most parameters better determined by factor of ~few.

M82 (Arbitrary Vertical Scaling)

Thursday, 9 July 2009

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SLIDE 47

The Planck Focal Plane

30 44 70 217 143 143 545

857

353

Thursday, 9 July 2009

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SLIDE 48

The Planck Focal Plane

30 44 70 217 143 143 545

857

353

Thursday, 9 July 2009

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SLIDE 49

Planck: Launched on 14 May!

Thursday, 9 July 2009

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SLIDE 50

Planck: Launched on 14 May!

Thursday, 9 July 2009

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SLIDE 51

New Technologies

 PolarBear: AT Lee

(Berkeley)

Antenna-coupled

bolometers

900 pixels @ 150 GHz,

3000 bolometers

Full use of useful 150

GHz Field-of-view

New challenges: 1000s

  • f bolometers (central

limit theorem to the rescue????)

Thursday, 9 July 2009

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SLIDE 52

EBEX

738 element array 139 element decagon Single TES

3 mm 8.6 cm

150 150 150 150 250 250 410

Meng, Lee, UCB 2.1 mm 30 cm

From individual bespoke detectors to 1,500 fabricated en masse

Thursday, 9 July 2009

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SLIDE 53

Ted Dunham, Lowell Observatory

Thursday, 9 July 2009

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SLIDE 54

Planck and The future of CMB Studies

□ Planck closes cosmological loopholes

■ qualitatively determine the background cosmogony

□ Opens astrophysics from cm to sub-mm □ Next:

■ high-sensitivity measurements of polarization (B-mode)

□ suborbital experiments (BICEP, SPIDER, EBEX, PolarBear) □ Cosmic Vision: BPol

□ All of these require active collaboration with other

wavelengths, techniques, theorists, data-analysts

Thursday, 9 July 2009