New Interacting Model and its Stability

Presentation on theme: "New Interacting Model and its Stability"— Presentation transcript:

1 New Interacting Model and its Stability
孙成一 西北大学现代物理研究所

2 New interacting DE model and its stability
Stability of Interacting DE Model 孙成一 西北大学现代物理研究所

3 New Interacting DE Model
: it was found Q was likely to change its sign around z=0.5. 孙成一 西北大学现代物理研究所

4 New Interacting DE Model
New Q: The model with the constant parameter of equation of state: 孙成一 西北大学现代物理研究所

5 New Interacting DE Model
Evolutions of DE and cold dark matter (CDM): 孙成一 西北大学现代物理研究所

6 New Interacting DE Model
Roughly Compare with Observational data of supernova type Ia and radio-galaxy: 孙成一 西北大学现代物理研究所

7 New Interacting DE Model
孙成一 西北大学现代物理研究所

8 New Interacting DE Model
Roughly compare with 7-year WMAP data: 孙成一 西北大学现代物理研究所

9 Stability of Interacting Model
The stability of the non-interacting model is determined by the square sound speed: and the adiabatic sound speed: Effective square sound speed in interacitng model: 孙成一 西北大学现代物理研究所

10 Stability of Interacting Model
Conserved effective energy-momentum tensors: Einstein equations: 孙成一 西北大学现代物理研究所

11 Stability of Interacting Model
The perturbed FRW metric in conformal Newtonian gauge: The perturbed parameters: 孙成一 西北大学现代物理研究所

12 Stability of Interacting Model
The evolving equations of perturbations: 孙成一 西北大学现代物理研究所

13 Stability of Interacting Model
Taking the geometric optic limit: 孙成一 西北大学现代物理研究所

14 Stability of Interacting Model
Eigenvalues: Even in the interacting model, the stabilities of the fluids are determined by the squared sound speed of DE: In the model with constant : , there exist adiabatic instabilities, as in the non-interacting models. 孙成一 西北大学现代物理研究所

15 New Interacting DE Model and its stability
Sun Cheng-Yi and Rui-Hong Yue, “New Interaction between Dark Energy and Dark Matter Changes Sign during Cosmological Evolution”, Phys. Rev. D 85 (2012), ; arXiv: [gr-qc].arXiv: [gr-qc]. 孙成一 西北大学现代物理研究所

16 谢谢！ 孙成一 西北大学现代物理研究所