51 citations · 315 across the 26 of their papers we have counts for
4 papers · 1 filter
Cosmological consequences of a scalar field with oscillating equation of state: A possible solution to the fine-tuning and coincidence problems
S. X. Tián
We propose a new dark energy model for solving the cosmological fine-tuning and coincidence problems. A default assumption is that the fine-tuning problem disappears if we do not i…
Quantization of the nonstandard propagating gravitational waves in the cosmological background
S. X. Tian, Zong-Hong Zhu
Detections of gravitational wave (GW) stimulate the discussion of how GWs propagate in the expanding Universe. General relativity predicts that GWs are massless and propagate at th…
Testing the Schwarzschild metric in a strong field region with the Event Horizon Telescope
S. X. Tian, Zong-Hong Zhu
Testing gravity theory in the strong field region becomes a reality due to the observations of gravitational waves and black hole shadows. In this paper, we discuss how to constrai…
Newtonian approximation and possible time-varying in nonlocal gravities
S. X. Tian, Zong-Hong Zhu
The Newtonian approximation with a nonvanishing nonlocal background field is analyzed for the scalar-tensor nonlocal gravity and nonlocal Gauss-Bonnet gravity. For these two theori…