What we have learnt from Planck

Wayne HuIAP, June 2019

(organizer’s title!)I learned(or how I learned to love tension)strange anomalies

curiositiesΛCDM?

slim pickings

What we have learnt from Planck

Wayne HuIAP, June 2019

I learned

What we have learnt from Planck

Wayne HuIAP, June 2019

(or how I learned to love tension)strange anomalies

curiosities

What we have learnt from Planck

Wayne HuIAP, June 2019

(or how I learned to love tension)anomalies

curiositiesΛCDM?

slim pickings^stop worrying and

Paradigm of Precision Cosmology.

-160 160 µK0.41 µK

tem

pera

ture

pola

rizat

ion

lens

ing

Planck (2018) I

• Precision measurementsand maps

– temperature

– polarization

– lensing

– 9 frequencies

• Control over systematics

– most recently polarization

• Accurate and precisetheoretical predictions

– Gaussian, adiabatic

– ΛCDM

Near Perfection in 6 Numbers.

10−3

10−2

10−1

100

101

102

103

D[µK2]

TT

EE

BB

TE

lensing

PlanckWMAPACTSPTACTPolSPTpol

POLARBEARBICEP2/Keck

BICEP2/Keck/WMAP/Planck

−200

−100

0

100

DTE[µK2]

2 150 500 1000 2000 3000 4000

Multipole

−0.5

0.0

0.5

1.0

1.5

107[(+1)]2C

φφ/2π

Planck (2018) I

• All this precisiondata described by6 ΛCDM parameters

– Ωch2: CDM

– Ωbh2: baryons

– θs: sound scale

– As: amplitude

– ns: tilt

– τ : reionization

• Measuredto sub percentprecision (except τ )

Predictive Power.

−100

−60

−20

20

60

100

∆D

[µK

2]

−8

−4

0

4

8

∆10

5C

[µK

2]

0 500 1000 1500 2000 2500

−8

−4

0

4

8

∆D

[µK

2]

Planck (2018) I

TE glitch

• Small residuals fromΛCDM in variousspectra

• Temp↔ polresiduals in ΛCDMwith reduced samplevariance

• Largely consistent,but with highprecision, moderatelysignificant deviations

• ∼ 2σ outliers, expectedbut some alsodrive parameters

Predictive Power• Predicts all other observables, which direct measurements test

0.24

0.25

0.26

YBBN

P

Aver et al. (2015)

Standard BBN

0.018 0.020 0.022 0.024 0.026

ωb

2.2

2.6

3.0

3.4

y DP

Cooke et al. (2018)

Planck TT,TE,EE+lowE

Standard BBN:

(Adelberger et al. 2011)(Marcucci et al. 2016)

Planck (2018) I,VI

0.5 1.0 1.5 2.0 2.5

0.90

0.95

1.00

1.05

1.10

(D/r d

rag)/(D

/r d

rag) P

lanck

6DFGS

SDSSMGS

SDSS quasars

WiggleZ

BOSSDR12

BOSS Ly-α (DM)

DES (DM)

DR14 LRG

−0.8

−0.4

0.0

0.4

0.8

JLA and Pantheon

Pantheon only

0.01 0.1 1

z z

z

−0.10

−0.05

0.00

0.05

µ−

µPlanck

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

0.2

0.3

0.4

0.5

0.6

0.7

0.8

fσ8

6dFGS

SDSS MGS

SDSS LRG

6dFGS+SnIa

GAMA

VIPERSBOSSDR12

WiggleZDR14 quasars

FastSound

BBN SNIa BAO

P(k) growth rate

baryon density

• Good agreement, even weak lensing, clusters, and yes H0 (< 10%)

Anchors Sink ΛCDM?• When distance ladder calibrated by CMB sound horizon, H0

discrepant with local measurements at 4.4σ (Riess et al 2019)

• Relative distances forward/backwards by ladder: CMB to BAO toSN isolating discrepancy as anchors (e.g. Aylor et al. 2018)

• Relative distances ∼ ΛCDM: little room for any new physics atintermediate redshifts to resolve

0.5 1.0 1.5 2.0 2.5

0.90

0.95

1.00

1.05

1.10

(D/r d

rag)/(D

/r d

rag) P

lanck

6DFGS

SDSSMGS

SDSS quasars

WiggleZ

BOSSDR12

BOSS Ly-α (DM)

DES (DM)

DR14 LRG

−0.8

−0.4

0.0

0.4

0.8

JLA and Pantheon

Pantheon only

0.01 0.1 1

zz z

−0.10

−0.05

0.00

0.05

µ−µPlanck

SNIa BAO

Soun

d H

orzo

n

Loca

l Anc

hors

0.0 0.5 1.0 1.5 2.0 2.5

56

62

68

74

H(z)/(1

+z) Local Anchors

Sound Horizon anchor tension

Planck (2018) I,VI

Driving in the Anchor• CMB anchor is sound horizon, must calibrate propagation time

• H(z < 103): with radiation, baryons fixed only Ωch2 unknown

• Ωch2 controls matter-radiation ratio and radiation driving from

potential decay due to Jeans stability

10 02515

Ψ

ks/π

damping

drivingtemperature

decay

Glitch and Oscillatory Residuals• Shifts in CMB anchor between low & high ` (Addison et al 2015)

• Low multipole glitch – deficit of power – looks like peaks shouldbe higher, more driving, less matter, higher H0

• High multipole oscillatory residuals: smoother acoustic peaks, lessdriving, more matter, lower H0

– also drives “lensing tension”: Pavel Motloch’s talk

−1.5

−1.0

−0.5

0.0

0.5

1.0

1.5

∆C

TT/σ

101 102 103

−15

−10

−5

0

5

−2∆

lnL

TT

ΛCDM TT ( < 1000)

Obied et al (2017)

glitchoscillatory

Planck Intermediate (2016) LI

penaltyΛCDM TT (all)

H0~70

Glitch and Large Angle Features• Exclude low ` < 30 glitch (Planck Intermediate 2016 LI)

• H0 falls, consistent with high multipoles within errors

• Alternately marginalize over possible features during inflation,mild ∆χ2 ∼ 12 improvement, but 5 params

• Likewise H0 returns to low value (Obied et al 2017)

−1.5

−1.0

−0.5

0.0

0.5

1.0

1.5

∆C

TT/σ

101 102 103

−15

−10

−5

0

5

−2∆

lnL

TT

ΛCDM TT ( < 1000)

SB TT

Obied et al (2017)

glitch

feature marginalized

oscillatory

Planck Intermediate (2016) LI

penalty

Driving and Oscillatory Residuals• Oscillatory residuals indicate smoother peaks (and persist even in

best fit ΛCDM)

• Driving sharpens the peaks

• Residuals indicate less driving, higher matter-radiation ratio

• Higher Ωch2, lower H0

10 02515

Ψ

ks/π

damping

drivingtemperature

decay

Driving and CDM• Signatures of CDM Ωch

2: TT amplitude and oscillatory residuals

• Polarization sharper test: projection effects for TT (Galli et al. 2014)

Obied et al (2017)

(+1)C

/2π

TT TE EE

3

−

−

0.

0.

2

−0.1

0.0

0.1

0.2

0.3

Ωbh2/σ Ωch

2/σ θMC/σ 500τ500τ

σ−1

dC

/dp

101 102 103

101 102 103

101 102 103

Polarization Signatures• Polarization sensitivity provides independent calibration using` < 1000 TE Planck data

• TE glitch at ` ∼ 165 enhances sensitivity, since lowering Ωch2

(raising H0) further raises predictions

Obied et al (2017)

−2

−1

0

1

2

∆C

TE

/σ

101 102 103

−15

−10

−5

0

5

−2∆

lnLT

TEE

ΛCDM TT ( < 1000)

SB TT

2σ glitch

Dark Radiation• Extra dark species whose energy density redshifts faster than

matter change sound horizon calibration

• Raise H(z < 103), lower sound horizon, raise H0 at fixed θs

• Additional driving from Jeans stable ∆Neff radiation compensatedby raising matter Ωch

2

10 02515

Ψ

ks/π

damping

drivingtemperature

decay

Driving and Damping• But damping provides second standard ruler in diffusion scale

• Random walk distance of photon scales as harmonic meanbetween horizon and mean free path

• Consistency check that ΛCDM passes and constrains anyadditional radiation ∆Neff

10 02515

Ψ

ks/π

damping

drivingtemperature

decay

Dark Exotica• Decreasing additional dark components during radiation

domination changes damping vs sound horizon

• Reconcile ratio if timed exactly right

0.00

0.03

0.06

0.09

10−5 10−4 10−3 10−2

a

frac

tion

of to

tal d

ensi

ty equality recombination

Lin et al (2019)da

mpi

ng se

nsiti

vity

horiz

on se

nsiti

vity

• Poulin et al (2018): specific anharmonic, periodic scalar potential

General Mechanism• Must compensate effect of raising Ωch

2 which reduces decay ofpotential

0.5

1.0

-(Ψ

+Φ

) aeq

-0.03

-0.02

-0.01

0.00

0.01

∆(Ψ

+Φ

)

k = 0.04/Mpc

10−5 10−4 10−3 10−2

a

raise CDM

General Mechanism• Dark exotica with relativistic sound speed, acoustic oscillations,

enhances decay

0.5

1.0

-(Ψ

+Φ

) aeq

-0.03

-0.02

-0.01

0.00

0.01

∆(Ψ

+Φ

)

k = 0.04/Mpc

10−5 10−4 10−3 10−2

a

ADE

4 Parameter Tuning• Tune the impact with sound speed (first dark acoustic peak) and

equation of state (redshifts away faster)

0.5

1.0

-(Ψ

+Φ

) aeq

-0.03

-0.02

-0.01

0.00

0.01

∆(Ψ

+Φ

)

k = 0.04/Mpc

10−5 10−4 10−3 10−2

a

sound speed

w

Reducing Tuning• Poulin et al (2018) 4 parameters, amplitude, time scale, c2

s and wmust be carefully tuned (top of oscillatory potential c2

s ↓)• Data favor something both more specific and generic: c2

s = w,transition to kinetic energy domination (Lin et al 2019)

~0.08 ρeq

PE: Hubble drag

KE: w=cs2

V,V

0.00

0.03

0.06

0.09acoustic DE

m φ2 2

10−5 10−4 10−3 10−2

a

locally

frac

tion

of to

tal d

ensi

ty

equality

Lin et al (2019)

Potential to Kinetic• With c2

s = w = 1 leaves 2 parameters: amplitude and slope ofpotential and requires kinetic energy redshift away (not oscillate)

• Amplitude ∼ 0.08ρeq and slope must be large enough to releasefrom Hubble drag

~0.08 ρeq

PE: Hubble drag

KE: w=cs2

V,V

0.00

0.03

0.06

0.09acoustic DE

m φ2 2

10−5 10−4 10−3 10−2

a

locally

frac

tion

of to

tal d

ensi

ty

equality

Lin et al (2019)

Fit and Predictive Signatures.

-1

-0.5

0

0.5

1

∆C

TT

/σ

CV

-1

-0.5

0

0.5

1

∆C

EE

/σ

CV

30 500 1000 1500 2000

-1

-0.5

0

0.5

1

∆C

TE

/σ

CV

Lin et al (2019)

• Fits joint data betterby ∆χ2 ∼ 12− 14

for 2-3 parameters

• Fits CMB itselfbetter, largely TE

• TE glitch ` ∼ 165

highly sensitive

• Dark componentredshifts away byrecombinationleaving nearlybare Ωch

2 signature

Potential Conversion of H0 Tension• Raises H0 to bring CMB and local anchors into better agreement

• Minor further improvements with additional parameters

• Posterior depends on parameter volume near ΛCDM, maximumlikelihood (ML) more reflective

• But mainly converts H0 question to “why this, why then”!

67.5 70.0 72.5 75.0H0

67.5 70.0 72.5 75.0H0

3 param2 param

4 param(oscil.)

ΛCDM

ML

Lin et al (2019)

Potential Conversion of H0 Tension• Raises H0 to bring CMB and local anchors into better agreement

• Minor further improvements with additional parameters

• Posterior depends on parameter volume near ΛCDM, maximumlikelihood (ML) more reflective

• Already limited by Planck TE polarization, distinguishing details

67.5 70.0 72.5 75.0H0

67.5 70.0 72.5 75.0H0

+POL

3 param2 param

4 param(oscil.)

ΛCDM

ML

Lin et al (2019)

Potential Conversion of H0 Tension• Raises H0 to bring CMB and local anchors into better agreement

• Minor further improvements with additional parameters

• Posterior depends on parameter volume near ΛCDM, maximumlikelihood (ML) more reflective

• EE residuals are ∼ 0.3 vs cosmic variance per multipole

-1

-0.5

0

0.5

1

∆C

EE

/σ

CV

30 500 1000 1500 2000

Lin et al (2019)

• Opportunity for testing ideas based on changing CMB anchor!

Summary• Planck and other precision CMB experiments have firmly

established ΛCDM as the standard model

• ΛCDM unreasonably effective and efficient in describing suite ofcosmological observables

• 6 numbers, mostly measured to sub percent precision, mostlyconsistent at this level with everything

• Tensions, anomalies and curiosities: imperfection is moreinteresting than perfection

• H0 at 4.4σ, can only be explained by changing one of the anchors

• CMB anchor is sound horizon and cross checked by damping scale

• Potential conversion illustrates designer difficulties, one or moreparameters per effect:

– look for predictive power of any explanation