CSSOS and dark energy Gong-Bo Zhao National Astronomical Observatories, China (NAOC) http://icosmology.info gbzhao@nao.cas.cn Oct 17, 2017 CSSOS workshop
CMB SNe CSSOS workshop 17/10/2017 2 Redshift surveys (BAO,RSD)
100+ Nobel Prizes since 1901! NASA CSSOS workshop 17/10/2017 3
100+ Nobel Prizes since 1901! NASA Huge discovery space in the dark sector! CMB (1978; 2006) Cosmic Acceleration (2011) Gravitational Waves (2017) CSSOS workshop 17/10/2017 4
The expansion of the Universe can accelerate if In GR, to add new ‘repulsive matter’, To modify General Relativity which contributes 70% total energy NASA/Jim Campbell/Aero-News Network Dark Energy Modified Gravity CSSOS workshop 17/10/2017 5
The expansion of the Universe can accelerate if In GR, to add new ‘repulsive matter’, To modify General Relativity which contributes 70% total energy NASA/Jim Campbell/Aero-News Network Dark Energy Modified Gravity LSS surveys can help break the degeneracy CSSOS workshop 17/10/2017 6
(2014-2020) DESI, PFS CSSOS workshop 17/10/2017 7 credit: Jean-Paul KNEIB
9, 376 deg 2 1, 372, 737 galaxies 294, 153 quasars (2014-2020) DESI, PFS CSSOS workshop 17/10/2017 8 credit: Jean-Paul KNEIB
What do redshift surveys measure? q , , j , , z A 3D galaxy map in z-space CSSOS workshop 17/10/2017 9
A 3D galaxy map in z-space x ( s ) P( k ) BOSS (Beutler et al, 2014) BOSS (Samushia et al, 2014) Landy & Szalay, 1993 Feldman et al, 1994 CSSOS workshop 10 17/10/2017
Baryonic Acoustic Oscillations (BAO) The standard Ruler CSSOS workshop 17/10/2017 11
Baryonic Acoustic Oscillations (BAO) source: Daniel Eisenstein’s web A bump at ≈ 150 Mpc formed on density profile. The BAO scale is cosmology- dependent! CSSOS workshop 17/10/2017 12
Latest BAO measurements Fourier space Configuration space BOSS (Alam et al), 2016, 1607.03155 CSSOS workshop 13 17/10/2017
BOSS (Alam et al), 2016, 1607.03155 CSSOS workshop 17/10/2017 14
Tomographic BAO measurements from BOSS DR12 GBZ, Wang, et al, (BOSS team), MNRAS 2017, 1607.03153 Wang, GBZ, et al, (BOSS team), MNRAS 2017, 1607.03154 CSSOS workshop 17/10/2017 15
Tomographic galaxy correlation function measurement BOSS (Wang, GBZ et al), 2016 CSSOS workshop 17/10/2017 16
BOSS (Yuting Wang, GBZ et al), 2016, 1607.03154 CSSOS workshop 17/10/2017 17
Latest BOSS tomographic BAO measurements BOSS (GBZ, Yuting Wang et al), 2016, 1607.03153 CSSOS workshop 17/10/2017 18
BOSS (GBZ, Yuting Wang et al), 2016, 1607.03153 CSSOS workshop 17/10/2017 19
BAO is key to Dark Energy a / a = − 4 π G • Negative ( ρ + 3 p ) > 0 3 pressure: ⇒ w ≡ p / ρ < − 1/ 3 • Candidates: Vacuum energy : w = -1 GBZ & Zhang, 2010 Dynamical fields: Quintessence (Ratra & Peebles, 1988): w (a)>-1 Phantom (Caldwell, 2002): w (a)<-1 Quintom (Feng, Wang and Zhang 2004): w (a) across -1 CSSOS workshop 17/10/2017 20
w(a) = w 0 +w a (1-a) eBOSS forecast (GBZ et al, 2015) CSSOS workshop 17/10/2017 21
w(a) = w 0 +w a (1-a) eBOSS forecast (GBZ et al, 2015) CSSOS workshop 17/10/2017 22
w(a) = w 0 +w a (1-a) + PFS, FoM=79 CSSOS workshop 17/10/2017 23
GBZ et al , Phys. Rev. Lett. 2012. Today 9 billion years ago CSSOS workshop 17/10/2017 24
L CDM dynamical DE Zhao et al., (BOSS collaboration), 2017 CSSOS workshop 17/10/2017 25 Nature Astronomy, 2017
CSSOS workshop 17/10/2017 26
Reconstruct w(a) non-parametrically Zhao et al., (BOSS collaboration), 2017 Nature Astronomy, 2017 CSSOS workshop 27 17/10/2017
CSSOS workshop 17/10/2017 28
The Redshift Space Distortion (RSD) We use redshift z to infer distance d in redshift surveys! CSSOS workshop 17/10/2017 29
Galaxies have peculiar motions due to the local overdensity on top of the Hubble velocity CSSOS workshop 17/10/2017 30
OVERDENSITY CSSOS workshop 17/10/2017 31
Kaiser, 1987 CSSOS workshop 17/10/2017 32
Latest BOSS DR12 RSD measurements BOSS (Alam et al), 2017, MNRAS, 1607.03155 CSSOS workshop 33 17/10/2017
Yuting Wang, GBZ et al (BOSS), 1709.05173 CSSOS workshop 17/10/2017 34
eBOSS Survey (started summer 2014) ² Dark-time observations ² Fall 2014 – Spring 2020 ² 1000 fibers per 7 deg2 plate ² Wavelength: 360-1000 nm, resolution R~2000 ² 1–2% distance measurements from baryon acoustic oscillations between 0.6 < z < 2.5 http://www.sdss.org CSSOS workshop 17/10/2017 35
Ata et al (eBOSS team including GBZ), MNRAS, 2017 CSSOS workshop 17/10/2017 36
Ata et al (eBOSS team including GBZ), MNRAS, 2017 CSSOS workshop 17/10/2017 37
Ata et al (eBOSS team including GBZ), MNRAS, 2017 CSSOS workshop 17/10/2017 38
Ata et al (eBOSS team including GBZ), MNRAS, 2017 CSSOS workshop 17/10/2017 39
eBOSS ability to constrain MG CSSOS workshop 17/10/2017 40
PFS ability to constrain MG CSSOS workshop 17/10/2017 41
Get some sense… CSSOS workshop 17/10/2017 42
GR CSSOS workshop 17/10/2017 43
f(R) CSSOS workshop 17/10/2017 44
Observational tests on multi-scales R < Mpc Mpc < R < Gpc R > Gpc Reconstructing w(z) Galaxy clustering, WL Cluster profiles using BAO, SN 0 E G = Ω 0 G eff 0.4 f G Newton 0.3 0.2 0.1 ADEPT+LSST 1.3<z<1.7 SKA 0 0.01 0.1 0.01 Pengjie Zhang et al., 2007, PRL GBZ et al., 2011, PRL GBZ et al., 2012, PRL CSSOS workshop 17/10/2017 45 GBZ et al., 2009, PRL Terukina et al., 2014, JCAP
Current surveys R < Mpc Mpc < R < Gpc R > Gpc Reconstructing w(z) Galaxy clustering, WL Cluster profiles using BAO, SN 740 SNe from SNLS Planck BOSS z<0.6 ~50 clusters CSSOS workshop 17/10/2017 46
Surveys in 5 years R < Mpc Mpc < R < Gpc R > Gpc Reconstructing w(z) Galaxy clustering, WL Cluster profiles using BAO, SN DES ~1000 SNe 5000 deg 2 IFU ~10000 spectra eBOSS 0.6<z<2.5 ~2000 clusters CSSOS workshop 17/10/2017 47
Surveys in 10 years R < Mpc Mpc < R < Gpc R > Gpc Reconstructing w(z) Galaxy clustering, WL Cluster profiles using BAO, SN DESIRE (Euclid)+LSST ~18k SNe TMT: 30 meter imaging LSST: 8.4 m , 20000 deg 2 imaging Euclid: 15000 deg 2 imaging + spectroscopic DESI: 4 m , 14000 deg 2 spectroscopic ~20000 clusters PFS : 8 m spectroscopic CSSOS workshop 17/10/2017 48 SKA : full sky radio
Surveys in 10 years R < Mpc Mpc < R < Gpc R > Gpc Reconstructing w(z) Galaxy clustering, WL Cluster profiles using BAO, SN CSSOS!! TMT: 30 meter imaging ~20000 clusters CSSOS workshop 17/10/2017 49
Summary Ø Galaxy surveys can provide key information for cosmology, and tomographic BAO/RSD analyses are crucial for DE and MG; Ø BOSS DR12 data (combined with others) show a hint of DE dynamics at 3.5 sigma level. The next step is to approve/falsify this signal at 5 sigma level, which is the threshold for a detection. CSST gives us the opportunity!! Ø CSST offers key information on the structure growth history of the Universe, which is essential for gravity tests. CSSOS workshop 17/10/2017 50
China built excellent instruments!! CSSOS workshop 17/10/2017 51
CSSOS makes China GREAT again in astronomy!! CSSOS workshop 17/10/2017 52
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