Determination
Download
1 / 36

Determination of cosmological parameters - PowerPoint PPT Presentation


  • 138 Views
  • Uploaded on

Determination of cosmological parameters. Gong-Bo Zhao, Jun-Qing Xia, Bo Feng, Hong Li Xinmin Zhang. IHEP, Beijing 06.8.30. Parameter space. Dark energy perturbation ??. Universe encoded in. Outline. 1. Dark energy perturbations when w crossing -1. 2.

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 ' Determination of cosmological parameters' - ama


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

Determination of cosmological parameters

Gong-Bo Zhao, Jun-Qing Xia, Bo Feng, Hong Li Xinmin Zhang

IHEP, Beijing06.8.30


Universe encoded in

Parameter space

Dark energy perturbation ??

Universe encoded in

2nd Sino-French Workshop


Outline
Outline

1

Dark energy perturbations when w crossing -1

2

Global fitting results of dark energy parameters

3

Dark energy & Inflation

4

Dark energy & neutrino mass limit

5

Bump-like dark energy

6

Searching for CPT violation

2nd Sino-French Workshop


Dark Energy:

* Negative pressure:

* Smoothly distributed, (almost ) not clustering

Candidates:

* Cosmological constant (or vacuum Energy)

cosmological constant problem!

* Dynamical Field: Quintessence, K-essence, Phantom etc

2nd Sino-French Workshop



Feng, Wang & Zhang

Astro-ph/0404224

Huterer & Cooray

Astro-ph/0404062

w

z

2nd Sino-French Workshop


Implication in model building of dark energy

If the running of w(Z), especially a transition across –1, confirmed

in the future, big challenge to the model building

* Vacuum : w=-1

* Quintessence:

* Phantom:

* K-essence: or but cannot across -1

(Vikman: astro-ph/0407107 )

A new scenanio of Dark Energy : Quintom (Zhang et al.Astro-ph/0404224)

For ex:

single scalar:

multi-scalar:

2nd Sino-French Workshop


Adding CMB,LSS data

Astro-ph/0407259,

Steen Hannestad,

Edvard Mortsell

2nd Sino-French Workshop


Include de perturbation when parametrizing the eos
Include DE perturbation when parametrizing the EOS

Ch. Yeche et al

Astro-ph/0507170

BIASED!

Including DE perturbation only

when w>-1

Seljak et al

Astro-ph/0407372

Neglect DE perturbations

2nd Sino-French Workshop


Strategies to handle the fluctuation of dark energy
Strategies to handle the fluctuation of Dark Energy

Difficulty:

2nd Sino-French Workshop


A way out based on quintom model
A way out based on quintom model

Here δ and θ are the density perturbation and the divergence of the fluid velocity respectively

Perturbation of DE is continuous during crossing!

Zhao et.al Phys.Rev.D 72,123515

2nd Sino-French Workshop


Our strategy to handle perturbations when w crosses 1
Our strategy to handle perturbations when w crosses -1

  • Quintessence – like perturbation

  • Phantom – like perturbation

  • Quintom-based perturbation

2nd Sino-French Workshop


Constrains on dark energy with SN Ia + SDSS + WMAP-1

Observing dark energy dynamics with supernova, microwave background and galaxy clustering

Jun-Qing Xia, Gong-Bo Zhao, Bo Feng, Hong Li and Xinmin Zhang

Phys.Rev.D73, 063521, 2006

2nd Sino-French Workshop


Comparision of global fitting results with SN Ia (Riess) and SNLS

WMAP+SDSS+SNLS

WMAP+SDSS+Riess

Jun-Qing Xia, Gongbo Zhao, Bo Feng, Hong Li and Xinmin Zhang

Phys.Rev.D73, 063521, 2006

2nd Sino-French Workshop


Relative error: ~9% SNLS

Relative error > 50% !!

Constrain on dark energy by WMAP (importance of perturbation)

2nd Sino-French Workshop



Gong-Bo Zhao SNLS, Jun-Qing Xia, Bo Feng and Xinmin Zhang, astro-ph/0603621

2nd Sino-French Workshop





A short summary on dark energy
A short summary on dark energy SNLS

  • Current data consistent with the cosmological constant

  • Dynamical models not ruled out

  • Data mildly favor the Quintom: a dynamical dark energy with

  • equation of state evolving and crossing -1

  • Questions: How dynamical dark energy in the global fitting affects the parameters of inflation, neutrino mass … ?

  • I. Interesting correlation between Inflation and dark energy parameters

  • Interesting correlation between dynamical dark energy and neutrino mass

2nd Sino-French Workshop


Dark energy inflation
Dark energy & Inflation SNLS

2nd Sino-French Workshop


WMAP3 + RIESS + SDSS (14 k-bands) SNLS

2nd Sino-French Workshop


Neutrino mass limit and dynamics of dark energy SNLS

Jun-Qing Xia, Gong-Bo Zhao, Bo Feng, Xinmin Zhang

In preparation

2nd Sino-French Workshop





Bump like dark energy
Bump-like dark energy SNLS

2nd Sino-French Workshop


EoS with feature: SNLS

2nd Sino-French Workshop


Probing this feature with GRB?? SNLS

2nd Sino-French Workshop


“Offline” analysis of the first 2 years SNLS

- Search the previous year imaging data for likely SNe either missed or not spectred for various reasons

- get z from host galaxy spectro (either by us or other projects) or get photo-z from imaging

- photo-id the SN

- add Ia to the Hubble diagram (in red)

very preliminary

Z=1.2 !

From Prof. Reynald Pain’s Hangzhou talk (May, 2006)

2nd Sino-French Workshop


Precise hubble diagram from sne ia from dr xiao feng wang s hangzhou talk may 2006
Precise Hubble diagram from SNe Ia SNLSFrom Dr. Xiao Feng Wang’s Hangzhou talk ( May, 2006)

2nd Sino-French Workshop


Searching for CPT violation SNLS

2nd Sino-French Workshop


predicting <TB> and <EB> SNLS

(Note here the notation: G ~ E, C~ B)

Bo Feng, Mingzhe Li , Jun-Qing Xia, Xuelei Chen and Xinmin Zhang

Phys. Rev. Lett. 96, 221302 (2006)

2nd Sino-French Workshop


Summary SNLS

  • Quintom Dark Energy Models:

  • Current data consistent with the cosmological constant

  • but mildly favor the Quintom: a dynamical dark energy with

  • Equation of state evolving and crossing -1

  • need more data and model building of Quintom dark energy

  • Interesting correlation between ns, alphas & DE

  • Interesting correlation between w1 neutrino mass

  • A model of Dark energy with featured EOS and its prediction (modulation)

  • on Hubble diagrams

  • V. Searching for Cosmological CPT Violation with new CMB data

2nd Sino-French Workshop


Thank You ! SNLS

2nd Sino-French Workshop


ad