slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Complementary Probes of Dark Energy PowerPoint Presentation
Download Presentation
Complementary Probes of Dark Energy

Loading in 2 Seconds...

play fullscreen
1 / 37

Complementary Probes of Dark Energy - PowerPoint PPT Presentation


  • 92 Views
  • Uploaded on

Complementary Probes of Dark Energy. Josh Frieman. Snowmass 2001. The History of 20 th Century Cosmology is littered with `detections’ of  which later evaporated. Man (and woman) cannot live by Supernovae alone. The implications of Dark Energy are so profound that

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Complementary Probes of Dark Energy' - caron


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Complementary Probes of

Dark Energy

JoshFrieman

Snowmass 2001

slide2

The History of 20th Century Cosmology is littered

  • with `detections’ of  which later evaporated.
  • Man (and woman) cannot live by Supernovae alone.
  • The implications of Dark Energy are so profound that
  • the SNe Ia results must be confirmed/extended by
  • multiple independent methods with:

* different systematic errors

  • * different cosmological parameter degeneracies
  • The Cosmic Microwave Background is not a panacea:
  • it has limited sensitivity to Dark Energy.
key issues
Key Issues
  • Is there Dark Energy?
  • Will the SNe results hold up?
  • What is the nature of the Dark Energy?
  • Is it  or something else?
  • How does w = pX/X evolve?
  • Dark Energy dynamics  Theory
physical effects of dark energy
Physical Effects of Dark Energy

Dark Energy affects expansion rate of the Universe:

Huterer & Turner

Dark Energy may also interact: long-range forces

Carroll

physical observables probing de
Physical Observables: probing DE
    • 1. Luminosity distance vs. redshift: dL(z) m(z)
  • Standard candles: SNe Ia
  • 2. Angular diameter distance vs. z: dA(z)
  • Alcock-Paczynski test: Ly-alpha forest; redshift correlations
  • 3. Number counts vs. redshift: N(M,z)
  • probes:
  • *Comoving Volume element dV/dzd
  • *Growth rate of density perturbations (z)
  • Counts of galaxy halos and of clusters; QSO lensing
slide6

Comoving Distance: r(z) =  dx/H(x)

In a flat Universe:

Luminosity Distance: dL(z) = r(z)(1+z)

Angular diameter Distance: dA(z) = r(z)/(1+z)

Comoving Volume Element: dV/dzd = r2(z)/H(z)

slide7

Sensitivity to Dark Energy equation of

state

Volume element

Comoving distance

Huterer & Turner

warning
Warning

Constraint contours depend on priors assumed

for other cosmological parameters

Conclusions depend on projected state of

knowledge/ignorance

slide13

Angular Diameter Distance

Transverse

extent

Angular

size

Intrinsically isotropic

clustering: radial and

transverse sizes are equal

Hui, Stebbins, Burles

slide14

Lyman-alpha forest: absorbing gas along LOS to distant Quasars

Clustering along line of sight

Cross-correlations between nearby

lines of sight

slide15

Sloan Digital Sky Survey

Projected constraints

from redshift space

clustering of

100,000

Luminous Red Galaxies

(z ~ 0.4)

Matsubara & Szalay

slide16

CMB Anisotropy:

Angular diameter

Distance to last

Scattering surface

Peak

Multipole

slide18

Evolution of Angular clustering as probe of

Angular diameter

Cooray, Hu, Huterer, Joffre

slide19

Volume Element as a function of w

Dark Energy  More volume at moderate redshift

slide20

Counting Galaxy Dark Matter Halos with the

DEEP Redshift Survey

10,000 galaxies at z ~ 1 with measured

linewidths (rotation speeds)

NB: must probe Dark matter-

dominated regions

Newman & Davis Huterer & Turner

slide21

Growth of Density Perturbations

Flat, matter-dominated

Open or w > -1

Holder

counting clusters of galaxies
Counting Clusters of Galaxies

Sunyaev Zel’dovich effect

X-ray emission from cluster gas

Weak Lensing

Simulations:

growth factor

slide23

Detection

Mass

thresholds

Haiman,

Holder, Mohr

slide24

Weak Lensing:

Optical

Multi-band

Surveys of

Varying

Depth

R ~ 25 (SDSS South)

R ~ 27.5

R ~ 30

Joffre, Frieman

slide25

Expected Cluster

Counts in a

Deep, wide

Sunyaev

Zel’dovich

Survey

Holder, Carlstrom, etal

slide26

Constraints from

a 4000 sq. deg.

SZE Survey

Mlim = 2.5 x 1014 h-1 Msun

Holder, Haiman, Mohr

weak lensing number cts of background galaxies
Weak Lensing:Number Cts of Background Galaxies

10

7

Number (per .5 mags)

5

10

3

10

1

10

Points: HDF

Curve: extrapolation

From SDSS luminosity

Function w/o mergers

16

18

20

22

24

26

28

Mag

slide28

Weak Lensing

S/N > 5 for

aperture mass

Assume NFW

Profiles

Conservative on

Number counts

R ~ 25 (SDSS South)

R ~ 27.5

R ~ 30

slide29

Abell

3667

z = 0.05

Joffre,

etal

wl detected clusters dn dz per sq deg

SDSS

R=27.5

R=30

WL Detected Clusters dn/dz per sq.deg.

100

dn/dz per sq. deg.

10

1

.5

1

1.5

2

2.5

3

z

slide31

Number of

Clusters

detected

above

Threshold

Here,

8 = 1

(will marginalize over)

R ~ 27.5; 20,000 sq. deg.

(co-added LSST or 1-year

wide-field SNAP)

R ~ 30; 16 sq. deg.

(nominal SNAP

in SNe mode)

R ~ 25,

200 sq. deg

(SDSS south)

slide32

Projected

Constraints

From

Cluster

Weak

Lensing

Large sky coverage

is critical

SNe

slide33

Cluster Weak Lensing:

  • Bring in Da Noise,
  • Bring in Da Funk
  • (account for:
  • projection effects
  • Fuzziness in

Mass limit,

also

variations in

NFW concentration

parameter)

Note: there is more information to be used than N(z)

slide34

Weak Lensing: Large-scale shear

Convergence

Power

Spectrum

1000 sq. deg.

to R ~ 27

Huterer

slide35

Projected

Constraints

From

Cosmic

Shear

1000 sq.deg.

R ~ 27

Caveat: systematics in low S/N regime

slide36

Clusters,

shear

halos

conclusions
Conclusions

Multiple probes of Dark Energy, including SNe,

should mature over the next 5-10 years

Independent confirmation of Dark Energy is within

sight

Good prospects for independent

constraints on the nature of the Dark Energy, with

varying systematics and nearly `orthogonal’ parameter

degeneracies