CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ...

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CMB lensing and delensing Anthony Challinor and Olivier Doré

Transcript of CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ...

Page 1: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

CMB lensing and delensing

Anthony Challinor and Olivier Doré

Page 2: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Current state of the art

Planck Collaboration 2016

4,000 resolved modesS/N = 40 (power spectrum)

Page 3: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Where we want to be …

>105 resolved modesS/N > 300 (power spectrum)

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TT/EB dominance in future

• EB particularly helpful for pol. noise < 5 μK arcmin- Polarization reconstructions less susceptible to extragalactic contamintion (e.g., tSZ) but more so to Galactic foregrounds

S/N = 40 S/N > 300

Page 5: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Goals for CMB lensing/delensing

• 4-pt φxφ (neutrino mass etc.)

• 3-pt φxLSS (growth of structure, dark energy, mitigation of systematics/self-calibration)

• Delensing (improve inflation constraints + Neff etc.)

• Halo lensing (cluster mass calibration at high redshift)

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Issues addressed in this session

• How do we achieve these goals?

• Survey requirements (resolution, sensitivity, frequency coverage, sky coverage)

• Space or ground?

• An ultimate diffuse lensing mission?

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Sensitivity and resolution

EB

TT

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N

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Pol. noise level

Page 8: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Cosmology from φxφ

Page 9: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Neutrino masses

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Allison+ 2015

• Complementary to optical weak lensing- Higher-z, mostly linear regime, no intrinsic-alignment issues

• Comparable precision on neutrino mass to e.g., Euclid lensing

Page 10: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Parameter degeneracies for mn

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CORE CORE+BAO

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Constraint on t important: degrades to 30 meV with Planck prior s(t) = 0.01

• Cosmic-variance-limited t [s(t) = 0.002] becomes limiting for Nmodes > 105

Page 11: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Issue I: extragalactic foregrounds• Issue in T-based reconstruction• tSZ and CIB

- tSZxtSZxφ and (tSZ)4 both important (van Engelen+ 2014)• Mitigation:

- Masking (loss of signal for tSZ)- Modelling (e.g., Planck for unclustered sources)- tSZ nulling (on gradient leg; Madhavacheril & Hill 2018)

0 500 1000 1500 2000 2500 L

−0.06

−0.04

−0.02

0.00

0.02

0.04

0.06

Fra

ctio

nal

CM

B L

ensi

ng B

ias

Standard masking, lmax = 3000

0 500 1000 1500 2000 2500 3000L

Aggressive masking, lmax = 2500

CIB2−κ corr.tSZ2−κ corr.CIB 4−pt.tSZ 4−pt.5 mJy

5x1014 Msol1 mJy1x1014 Msol

150 GHz

van Engelen+ 2014

Page 12: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Issue 2: Galactic foregrounds

• Main issue for EB reconstruction

• Care (mainly) about 4-pt non-Gaussianity on intermediate and small scales

- Very limited empirical information on these scales

• Mitigation:- Multi-frequency cleaning- “Local” analysis with foreground power included in lensing filters to downweight contaminated modes

Page 13: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Results on 150 GHz simulations

• Data-derived simulations (Planck FFP8) but do not capture small-scale NG from small-scale B field

No dust Worst 600-deg2 dust field Dust inc. in lensing filters

AC+CORE 2017

Page 14: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Requirements for φxφ• Mostly care about Nmodes for power spectrum science

- Generally favours large sky coverage at fixed Ndet

• Neutrino mass requires precise t measurement- Low-l E-mode polarization from space (e.g., LiteBIRD)- Precision on mass (with BAO) saturates around Nmodes~105

- kSZ from patchy reionization (Ferraro & Smith 2018)

• Multi-frequency at high resolution prudent but less demanding than for low-l B-mode science

- Need for Galactic simulations properly capturing small-scale non-Gaussianity

Page 15: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Cosmology from φxLSS

Page 16: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Giannantonio+ 2016

Growth of structurehCMB⌃i / b(z)D2(z)h⌃⌃i / b2(z)D2(z)

Page 17: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

0 500 1000 1500 2000 2500 3000

0.0

0.5

1.0

1.5

2.0

ℓC

κCM

Bκgal

ℓ(×

10−6) Planck

WMAP 9

Hand+2013; see also Liu & Hill 2015

• Current detections around 3s • Will improve to >50s with e.g., DES 5-yr x SPT-3G• X-correlation more immune to additive systematic effects• Full joint analysis can calibrate multiplicative bias effects in shape measurement and intrinsic alignments

Kirk+ 2016

Galaxy lensing-CMB lensing

Page 18: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Issue: extragalactic foregrounds

• tSZ and CIB are issues in T-based reconstruction• Only, e.g., tSZxtSZxLSS now enters • Mitigation:

- Masking - Modelling - tSZ nulling (on gradient leg; Madhavacheril & Hill 2018)

h�(c+ f, c+ f)⇥ LSSi = h�(c, c)⇥ LSSi+ h�(f, f)⇥ LSSi= h�⇥ LSSi+ h�(f, f)⇥ LSSi

<latexit sha1_base64="BBMehG89NJikxIFceU4FgOlTNv4=">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</latexit><latexit sha1_base64="BBMehG89NJikxIFceU4FgOlTNv4=">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</latexit><latexit sha1_base64="BBMehG89NJikxIFceU4FgOlTNv4=">AAAC33icnVJNbxMxEPVuaSkLbQMcuVhEoFaNog2KBEggVeqFA4eidkmleBV5ndnEite7smcR0SqnXjjQqlf+Fjd+CVecj0r9SHpgpJFHb97zs8dOCiUthuEfz197sL7xcPNR8PjJ1vZO7emzrzYvjYBI5Co3pwm3oKSGCCUqOC0M8CxR0ElGh9N+5xsYK3N9guMC4owPtEyl4OigXu0vU1wPFFA25FixYignu2I/bbjcYygzsJQhfMfq8/HxhJk59/VHukzWEKsl+8sUaeMeE8aC6z5OQO9w6X9v36vVw2Y7nAa9W7SaszWsk0Uc9Wq/WT8XZQYaheLWdlthgXHFDUqhYBKw0kLBxYgPoOtKzZ1tXM0eaEJfOaRP09y41Ehn6HVFxTNrx1nimBnHob3dm4LLet0S03dxJXVRImgxN0pLRTGn09emfWlAoBq7ggsj3VmpGHLDBbo/EbghXN2Uri6iN833zdaXdv3gw2Iam+QFeUl2SYu8JQfkEzkiERFe7J15P71zP/F/+Bf+5ZzqewvNc3Ij/F//ADDP5wI=</latexit><latexit sha1_base64="BBMehG89NJikxIFceU4FgOlTNv4=">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</latexit>

Desired x-correlation Fg-fg-LSS bispectrum

Page 19: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Requirements for φxLSS

• Overlap with optical surveys

• Generally favours wide survey

• Galactic foregrounds less of an issue (no bias but can inflate errors)

• Extragalactic foregrounds in TT require cleaning/ modelling/agressive masking

- Gradient-leg cleaning (e.g., with Planck)

Page 20: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Delensing

Page 21: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Lensing and inflation constraints

Factor 6.5 hit by lensing for both scales (no signal c.v.)

Lensing relatively more important for recombination signal for non-zero r

Lensing limits ability to test these models at high significance

No lensing

AC+CORE Collaboration 2017

Page 22: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

• Gradient approximation accurate for large-angle B-modes• Residual lensing has power spectrum

Delensing the CMB

• Remap CMB with Wiener-filtered tracer I of CMB lensing

�W = W ⇤ IXdelens

(

ˆn) = Xobs

(

ˆn�rˆ�W)

⇡ Xunlens

(

ˆn+r(�� ˆ�W| {z } )) + noise

Residual lensing

C��, delensl = C��

l (1� ⇢2l )

⇢2l =

⇣CI�

l

⌘2

CII, totl C��

l

Page 23: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Scales for BB delensingCBB,delens

l

CBB,lensl

⇡X

L

@ lnCBB,lensl

@ lnC��L

�1� ⇢2L

Page 24: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Internal delensing with Planck

Carron, Lewis & AC 2017

100 101 102 103

`

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

✏ `

�TT

�MV

�P

`vTT`

`vEE`

`vBB`

Scales for peak smoothing

Scales for lensing B-modes

Reconstruction very noisyEffic

ienc

y r l

2

Page 25: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Improvements from internal delensing

4 6 8 10 12 14

✓fwhm [arcmin]1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6↵

=�(r

) nodel

ens/

�(r

) del

ens

2 µK-arcmin2 µK-arcmin, it.3 µK-arcmin3 µK-arcmin, it.

Factor 1.6–2 improvement by internal delensing with future satellites; better from ground

Fact

or b

y w

hich

del

ensi

ng

impr

oves

s(r

) fo

r r=

0

AC+CORE Collaboration 2017

Page 26: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Bias from dependent recon. noise• Consider B-mode template delensing with XY estimator:

Carron, Lewis & AC 2017; see also Sehgal+ 2017; Teng+ 2011; Namikawa 2017

Bdelens ⇠ B � EW �W(X,Y )

• Power spectrum after delensing:

CBBdelens ⇠ hBBi � 2hBEW �W(X,Y )i+ hEW �W(X,Y )EW �W(X,Y )i

If reconstruction noise were independent of CMB, just gives usual

2hBEW�Wi

In practice, reconstruction dependent on CMB giving dominant bias

2BEW �W(X,Y ) + 2BEW �W(X,Y )

• r-dependent bias if X or Y=B and overlapping scales

Page 27: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Modelling the bias

• Non-trivial power spectrum covariance also

200 400 600 800 1000 1200 1400`

2

3

4

5

6

CB

B`

[10�

6µK

2]

analytic CBB,resl with � indep. of CMB

hCBB,resl i400sims with �EB

green + hBtempBtempic,IV

green + hBtempBtempiG

green + hBtempBobsiG

green + three corrections

Baleato-Lizancos+AC in prep.; see also Namikawa 2017

Delensed power from sims

Expectation for independent recon. noise

2 arcmin beam; 7 µKarcmin noise

Including dominant bias term

B-mode noise power level

Page 28: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

More optimal lens reconstruction

4 6 8 10 12 14

✓fwhm [arcmin]1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6↵

=�(r

) nodel

ens/

�(r

) del

ens

2 µK-arcmin2 µK-arcmin, it.3 µK-arcmin3 µK-arcmin, it.

Quadratic estimator for lensing reconstruction

Fact

or b

y w

hich

del

ensi

ng

impr

oves

s(r

) fo

r r=

0

AC+CORE Collaboration 2017

“Optimal” lensing reconstruction

Page 29: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

External delensingGNILC 353 GHz + WISE co-add

-0.1 0.1CMB lensing convergence

GNILC 353 GHz + WISE + Planck lens co-add

-0.1 0.1CMB lensing convergence

500 1000 1500 2000

l

0.0

0.1

0.2

0.3

0.4

0.5

0.6

⇢2 l(S

quar

edC

orre

lati

onC

oe�

cien

t)

CIB contribution

WISE contribution

Planck contribution

CIB + WISE + Planck

Contribution to the low-l CBBlCIB+gal.

CIB+gal.+CMB

Byeonghee+ 2017

• Need high-z sources (CIB, LSST galaxies etc.)• Residual power can be modelled from empirical spectra

Remove around 40% of lensing power with signal-dominated E-modes

Page 30: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Requirements for BB delensing

• Overlap of high-resolution survey with degree-scale B-mode survey (e.g., CMB-S4)

• Sensitivity better than 5 µKarcmin

• Bias from non-Gaussian Galactic foregrounds not yet quantified

- Residual B-mode power involves up to 6-pt function

Page 31: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Halo lensing

Page 32: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Halo lensing

Baxter+ 2017

6.5s detection of cluster lensing

• Statistical mass calibration for large samples at high redshift

See also Baxter+ 2015; Planck Collaboration 2016; Madhavacheril+ 2015; Geach & Peacock 2017

Page 33: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Requirements for halo lensing

• Arcmin resolution• Rejection of tSZ and IR emission from cluster galaxies• Large area

101

0.01

0.1

1

∆T=∆P/21/2 (µK’)

∆M

/M (

N/1

03)1

/2

TT

ET

EB

θFWHM=1’; l<lbeam

Hu+ 2007

Frac

tiona

l mas

s er

ror

on 1

000

clus

ter

stac

k

Page 34: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Ultimate diffuse lensing mission?

• To write

de Zotti+2016

6

FIG. 3: Ratio between line luminosity, L, and star formation rate, M�, for various lines observed ingalaxies and taken from Table 1 of [23]. For the first 7 lines this ratio is measured from a sample oflow redshift galaxies. The other lines have been calibrated based on the galaxy M82. Some weakerlines, for example for HCN, have been omitted for clarity.

the fluctuations from a particular redshift by cross correlating the emission in two di�erentlines. If one compares the fluctuations at two di�erent wavelengths, which correspond to thesame redshift for two di�erent emission lines, the fluctuations will be strongly correlated.However, the signal from any other lines arises from galaxies at di�erent redshifts which arevery far apart and thus will have much weaker correlation (see Figure 4). In this way, onecan measure either the two-point correlation function or power spectrum of galaxies at sometarget redshift weighted by the total emission in the spectral lines being cross correlated.

The cross power spectrum at a wavenumber k can be written as,

P1,2(⇥k) = S1S2b2P (⇥k) + Pshot, (1)

where S1 and S2 are the average fluxes in lines 1 and 2 respectively, b is the average biasfactor of the galactic sources, P (⇥k) is the matter power spectrum, and Pshot is the shot-noisepower spectrum due to the discrete nature of galaxies. Visbal & Loeb (2010) showed thatthe root-mean-square error in measuring the cross power spectrum at a particular k-modeis given by,

�P 21,2 =

1

2(P 2

1,2 + P1totalP2total), (2)

where P1total and P2total are the total power spectra corresponding to the first line andsecond line being cross correlated. Each of these includes a term for the power spectrum ofcontaminating lines, the target line, and detector noise. Figure 5 shows the expected errors inthe determination of the cross power spectrum using the OI(63 µm) and OIII(52 µm) lines ata redshift z = 6 for an optimized spectrometer on a 3.5 meter space-borne infrared telescopesimilar to SPICA, providing background limited sensitivity for 100 di�raction limited beams

Visbal, Trac, Loeb 2011

There is more to extra-galactic galaxies than CIB!

Page 35: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Ultimate diffuse lensing mission?

Serra, OD, Lagache 2017

Potentially a challenge to measure the primordial distortions

Page 36: CMB lensing and delensing - kiss.caltech.edu · Goals for CMB lensing/delensing •4-pt φxφ (neutrino mass etc.) •3-pt φxLSS (growth of structure, dark energy, mitigation of

Ultimate diffuse lensing mission?

• To write

Serra, OD, Lagache 17

Schaan, Spergel, Ferraro 2018Foreman+ 2018

• But an opportunity to perfectly delense and measure the growth of structures…• We are at a KISS workshop after all!