Precision Cosmology
Cosmic Controversy @ Chicago 10-06-2019

Chihway Chang
University of Chicago / KICP

1

Precise & Accurate Cosmology
Cosmic Controversy @ Chicago 10-06-2019

Chihway Chang
University of Chicago / KICP

2

How to Make Progress Going Forward?
• Improving constraints (stats. and sys. errors) to stress-test LCDM
• Looking into new directions and new approaches!3How to Make Progress Going Forward?
• Improving constraints (stats. and sys. errors) to stress-test LCDM
• Looking into new directions and new approaches!4How to Make Progress Going Forward?
• Improving constraints (stats. and sys. errors) to stress-test LCDM
• Looking into new directions and new approaches!5How to Make Progress Going Forward?
• Improving constraints (stats. and sys. errors) to stress-test LCDM
• Looking into new directions and new approaches

I will be focusing on weak lensing
analyses in galaxy surveys, but
obviously this applies to everything…
!6

Finished
Ongoing

Where we Stand
SDSS

FutureYou Are HereDLS
CFHTLenS

KiDSDESHSCDESI
LSST
EuclidTime

WFIRSTFinishedOngoing

Where we StandSDSSFutureYou Are HereDLS
CFHTLenS

KiDS
DES
HSC
DESI
LSSTEuclid

Time“Stage II”“Stage III”

“Stage IV”

WFIRSTFinishedOngoing

Where we StandSDSS

FutureYou Are HereDLS
CFHTLenS

KiDS
DES
HSC

Talk from Gary Bernstein,
Hendrik Hildebrandt,
Alexie Leauthaud

DESI
LSST
EuclidTime

WFIRSTWeak Lensing Surveys

BSERVATIONAL RESULTS AND COSMOLOGICAL CONSTRAINTS

1.1

COSMOS

1.0

100 deg2
CFHTLS/CFHTLenS
SDSS-Stripe82
DLS
SDSS-DR7
CMB

41

DES
KiDS
HSC8 (⌦m /0.3)

↵0.9

0.8

0.7

0.6

0.5

Extended from Kilbinger (2015)
20062008

2010

2012year

Figure 7. Mean and 68% error bars for the parameter2014

2016!10↵(⌦ /0.3) , for various cosmic shear

2018

2020

Weak Lensing Surveys

BSERVATIONAL RESULTS AND COSMOLOGICAL CONSTRAINTS

1.1

COSMOS

1.0

100 deg2
CFHTLS/CFHTLenS
SDSS-Stripe82
DLS
SDSS-DR7CMB

S8 ⌘<latexit sha1_base64="NgxRAJ8lNxYf4ELJ5NJEVK1bSrQ=">AAACFnicdZDLSgMxFIYzXmu9VV26CRahLhwz1kvdiW7cqWit0Kklk57WYDIzJhmhDPMUbnwVNy4UcSvufBvTWkFFD4T8fP85JOcPYsG1IeTdGRoeGR0bz03kJ6emZ2YLc/NnOkoUgyqLRKTOA6pB8BCqhhsB57ECKgMBteBqv+fXbkBpHoWnphtDQ9JOyNucUWNRs7B60kwrGfbhOuE32Ne8I2mPlPxDCR0rZbZG3PLKRUrczaxZKNqLeDtbBBOX9KsvKl7Zw96AFNGgjpqFN78VsURCaJigWtc9EptGSpXhTECW9xMNMWVXtAN1K0MqQTfS/loZXrakhduRsic0uE+/T6RUat2Vge2U1Fzq314P/uXVE9OuNFIexomBkH0+1E4ENhHuZYRbXAEzomsFZYrbv2J2SRVlxiaZtyF8bYr/F2frrkdc73ijuLs3iCOHFtESKiEPbaNddICOUBUxdIvu0SN6cu6cB+fZeflsHXIGMwvoRzmvH150njY=</latexit>

0.5(⌦/0.3)
8m41

DESKiDSHSC8 (⌦m /0.3)↵

0.90.80.7

0.60.5Extended from Kilbinger (2015)
2006

2008

2010

2012year

Figure 7. Mean and 68% error bars for the parameter2014

2016!10↵(⌦ /0.3) , for various cosmic shear

20182020

Weak Lensing Surveys

BSERVATIONAL RESULTS AND COSMOLOGICAL CONSTRAINTS

1.1

COSMOS

1.0100 deg2
CFHTLS/CFHTLenS
SDSS-Stripe82
DLS
SDSS-DR7CMB

S8 ⌘<latexit sha1_base64="NgxRAJ8lNxYf4ELJ5NJEVK1bSrQ=">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</latexit>

0.5(⌦/0.3)
8m41

DES
KiDS
HSC8 (⌦m /0.3)

↵

0.9

0.8

0.7

0.6

0.5

Extended from Kilbinger (2015)
2006

2008

2010

2012
year

First detection, 2000
Figure 7. Mean and 68% error bars for the parameter2014

2016!10↵(⌦ /0.3) , for various cosmic shear

20182020

Weak Lensing Surveys

BSERVATIONAL RESULTS AND COSMOLOGICAL CONSTRAINTS

41

area, depth, analysis techniques, sizeof collaboration, error bars (?!)
1.1

COSMOS

1.0100 deg2
CFHTLS/CFHTLenS
SDSS-Stripe82
DLS
SDSS-DR7CMBS8 ⌘<latexit sha1_base64="NgxRAJ8lNxYf4ELJ5NJEVK1bSrQ=">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</latexit>

0.5(⌦
/0.3)
8mDESKiDSHSC8 (⌦m /0.3)↵0.90.8

0.7

0.6

0.5

Extended from Kilbinger (2015)
20062008

2010

2012yearFirst detection, 2000
Figure 7. Mean and 68% error bars for the parameter2014

2016!10↵(⌦ /0.3) , for various cosmic shear

2018

2020

Weak Lensing Surveys

BSERVATIONAL RESULTS AND COSMOLOGICAL CONSTRAINTS

41

area, depth, analysis techniques, sizeof collaboration, error bars (?!)
1.1

COSMOS

1.0

100 deg2
CFHTLS/CFHTLenS
SDSS-Stripe82
DLSSDSS-DR7
CMB

S8 ⌘<latexit sha1_base64="NgxRAJ8lNxYf4ELJ5NJEVK1bSrQ=">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</latexit>

0.5(⌦/0.3)8mDES
KiDSHSC8 (⌦m /0.3)

↵

0.9

0.8

0.7

0.6

0.5

Extended from Kilbinger (2015)
2006

2008

2010

2012
year

First detection, 2000
Figure 7. Mean and 68% error bars for the parameter2014

2016!10↵(⌦ /0.3) , for various cosmic shear

20182020

DLS/CFHTLenS/DES-SV/KiDS-450
Re-analysis

AAUnified
UnifiedAnalysis
AnalysisofofFour
FourCosmic
CosmicShear
ShearSurveys
SurveyCC, Wang, Dodelson et al. (2019)00..909000..60
60

0..75
75

S8S
0 8!110.
0.8
8

0.
0.6
6

0.
0.4
4mm

1.
1.25
25

1.
1.25
25

m m

MatchedMatched(i)(i)

0.
0.2
2

1. 0. 41.50 0.45
50 5

0.
0.8
8

0.
0.6
6

0.
0.4
4

Published
PublishedNominal
Nominal

0.
0.2
2

1. 0.
1.50 0.45
50 45

0.
0. 60
60

.
0. 75
75

S80 S80.
0. 9090

11..0505

DLS
DLS
CFHTLenS
CFHTLenS
DES-SVDES-SV
KiDS-450
KiDS-450

1.
1. 05
05

DLS
DLS
CFHTLenS
CFHTLenS
DES-SVDES-SV
KiDS-450
KiDS-450

DLS/CFHTLenS/DES-SV/KiDS-450
Re-analysis

AAUnified
UnifiedAnalysis
AnalysisofofFour
FourCosmic
CosmicShear
ShearSurveys
SurveyCC, Wang, Dodelson et al. (2019)00..9090
00..60
60

0..75
75

S8S
0 8

0.
0. 60
60

.
0. 75
75

S80 S80.
0. 90
90

1
1..05
05

DLS
DLS
CFHTLenS
CFHTLenS
DES-SVDES-SV
KiDS-450
KiDS-450

1.
1. 05
05

DLSDLSCFHTLenS
CFHTLenS
DES-SVDES-SV
KiDS-450
KiDS-450

!110.
0.8
8

0.
0.6
6

0.
0.4
4mm

1.
1.25
25

1.
1.2525m m

0.
0.2
2

1. 0. 41.50 0.45
50 5

0.
0.8
8

0.
0.6
6

0.
0.4
4

0.
0.2
2

1. 0.
1.50 0.45
50 45

1) Was the agreement too good?
Published
MatchedPublishedNominal
NominalMatched(i)(i)2) Many things generate half-sigma shifts: scale cuts, priors, covarianceDES/KiDS Re-analysis

Troxel, Krause, CC et al. (2019)

Joudaki et al (2019)

DES/KiDS Re-analysis
Troxel, Krause, CC et al. (2019)
Joudaki et al (2019)1) Are we subconsciously trying to make things agree?
2) WL does not strongly constrain w yet3) A healthy culture of making data and code publicFinishedOngoing

Where we StandSDSS

FutureYou Are HereDLS
CFHTLenS

KiDS
DES
HSC
DESI
LSST
EuclidTime

WFIRSTNext 10+ years…

Credit: Olivier Doré!14

Next 10+ years…

Credit: Olivier Doré!14

The Large Synoptic Survey Telescope
LSST is a ground-based imaging survey
scheduled to start commissioning ~2020
science run ~2023
6 filter bands (ugrizY), 10 sq. deg FOV,
10 years, ~3 day cadence, 20,000 sq. deg, i~27
Wide field and time-domain science

https://www.lsst.org/news/see-whats-happening-cerro-pachon

May 2018

June 2019!15

DOE LSST Camera Project: ~95% complete (by budget)
NSF LSST Site & Telescope: ~70% complete (by budget)

The Large Synoptic Survey Telescope
LSST
DESC Requirements
The LSST Dark Energy Science Collaboration has been
extremely
active inpreparing the various science analysis pipelines and coordinating manpower.

Clusters Y10
SL Y10Stage III
SN Y103x2pt Y10
LSST all+Stage III01wa12

Realistic forecast show that combining
the major probes in LSST, we achieve
the Stage IV goals in Dark Energy
constraints (~10x Stage II)

1640

4

80.

0.

0.

0.

2

The LSST DESC Science
Requirement Document (2018)
w0

Something a Little Different• GR and LCDM have passed many many tests, but often in these regimes:• Large scales• Gaussian information• Fully collapsed structures• Single dataset• Measurements in areas beyond these are harder, but we will get better data
and better analysis techniques in the next 10 years!

!17Non-Gaussian Information+70+60+50+40+30+20+100+350+340

3Gruen et al. (2018)

230
1S/N

040

12

CC et al. (2018)

E ; 0.2 < z < 1.3
503+70+60+50+40+30+20+100+350+340

3

Density split statistics

230

Peak statistics

1S/N

0Minkowski functionals

40Moments12

 ; 0.2 < z <Kacprzak
et1.3 al. (2016)
B50

3Preliminary
Petri et al. (2013)18Gatti et al. (in prep)Non-Gaussian Information

Vikram et al., CC et al. (2015)!19

Weak Lensing Projected Mass

DESScienceVerification(2013)

Non-Gaussian Information
Weak Lensing Projected MassDES
Year 1(2014)

CC et al. (2018)!20

Non-Gaussian Information

DESYear 3(2016)

Credit: DES Collaboration!21

Weak Lensing Projected Mass

PreliminaryCosmology from Moments ofWeak Lensing Maps
Gatti, CC, Friedrich, Jain et al. (in prep)

One of the first analyses of WL
non-Gaussian statistics thatrigorously tests realistic
observational effects the same
way we are treating two-pointstatistics in state-of-the-art data.
Obviously still early days andlots of work ahead, but recall:first detection of cosmic shear
was only 20 years ago!

PreliminaryCombining Probes
Requiring independent dataset to tell the same story is a powerful way oftesting LCDM.

Credit: Yuuki Omori

DES, SPT et al. (2019)

Talk from Alexander Krolewski!23Combining Probes
DES, SPT et al. (in prep)

Next analysis will be better!
Improvement in CMB lensing
map and galaxy sample.
Tanoglidis, CC, Frieman (2019)

PreliminaryCombining ProbesDES,SPT et al. (2019)

Controlling systematics:- Self-calibration- Astrophysical systematics

Koukoufilippas et al. (2019)
Also Pandey et al. (2019)

A Unified Analysis of Four Cosmic Shear Surveys

1.
90
0.
75

S80.

60

0.

75

0.

60

0.

45

Matched (i)

680.

40.
m

680.

4
0.

0.

2

80.

0.

6

40.
m

0.

2
0.

0.

0.

50

50

0.

0.

75

75

88

1.

1.

00

00

1.

1.

25

25

m

0.

250

0.
80.

1.

6

40.

0.

20.

1.

50

0.

45

Published Nominal

0.

S80.

901.

05

DLS
CFHTLenS
DES-SV
KiDS-45005

SummaryDLS
CFHTLenS
DES-SV
KiDS-450

17mFigure 11. Final comparison of the cosmological constraints from the four surveys according to the literature (Published Nominal, left) and according to ourunified analysis framework (right, Matched) – we show the marginalized constraints for Wm , S8 ⌘ s8 (Wm /0.3)0.5 and s8 for the four cosmic shear surveys. In
the right panel, we use Gaussian analytic covariances, conservative scale cuts and the KiDS-450 priors. We note that for the CFHTLenS Published Nominal
constraints, we show all three settings MIN (solid), MID (dashed) and MAX (dotted) in Joudaki et al. (2017a).

Table 6. Comparison metrics corresponding to the right panel of Fig. 11.
That is, all analysis choices matched: Gaussian C OSMO L IKE covariancematrix, conservative scale cuts, same IA treatments, and KiDS-450 cosmological priors. For the S8 values, we list the mean and the 16% and 84%
confidence intervals.

!26