51 citations · 315 across the 26 of their papers we have counts for
17 papers · 1 filter
Black holes with conical infinity in gravitational caloric theory
S. X. Tian, Zong-Hong Zhu
Whether gravitational caloric theory admits spherical black-hole solutions beyond Schwarzschild remains open. A well-defined black-hole solution requires both a regular horizon and…
Gravitational caloric theory: From early dark energy to a wide variety of gravitational phenomena
S. X. Tian
We propose gravitational caloric theory (GCT) --- an extension of general relativity that features a vector field sourced by and non-minimally coupled to the fluid sector whi…
Inflation driven by a bare cosmological constant and its graceful exit
Chengsheng Mu, Shuxun Tian, Shuo Cao +1
Vacuum energy, a prediction of quantum field theory, manifests itself as a cosmological constant in general relativity. In this Letter, we propose a novel inflationary scenario dri…
Early dark energy triggered by spacetime dynamics that encodes cosmic radiation-matter transition
Changcheng Jing, Shuxun Tian, Zong-Hong Zhu
Early dark energy (EDE), introduced at the epoch of matter-radiation equality to alleviate the Hubble tension, has posed a new coincidence problem: why EDE appears at matter-radiat…
Time evolution of the local gravitational parameters and gravitational wave polarizations in a relativistic MOND theory
Shuxun Tian, Shaoqi Hou, Shuo Cao +1
The recently proposed Skordis-Złośnik theory is the first relativistic MOND theory that can recover the success of the standard CDM model at matching observations of the cosmic…
Gravitation with modified fluid Lagrangian: Variational principle and an early dark energy model
S. X. Tian, Zong-Hong Zhu
Variational principle is the main approach to obtain complete and self-consistent field equations in gravitational theories. This method works well in pure field cases such as $f(R…
Cosmological consequences of a scalar field with oscillating equation of state. IV. Primordial nucleosynthesis and the deuterium problem
S. X. Tian
We study the primordial nucleosynthesis (BBN) in the stepwise scalar field model proposed by Tián [arXiv:1912.13208, Phys. Rev. D 101, 063531 (2020)], which provides a multiacceler…
Early dark energy in -essence
S. X. Tian, Zong-Hong Zhu
Early dark energy (EDE) that becomes subdominant around the epoch of matter-radiation equality can be used to ease the Hubble tension. However, there is a theoretical problem that…
Cosmological consequences of a scalar field with oscillating equation of state. II. Oscillating scaling and chaotic accelerating solutions
S. X. Tian
Multiacceleration scenario can be used to solve the cosmological coincidence problem. In this paper, after considering the early radiation era, we revisit the cosmological dynamics…
Non-full equivalence of the four-dimensional Einstein-Gauss-Bonnet gravity and Horndeksi gravity for Bianchi type I metric
S. X. Tian, Zong-Hong Zhu
The four-dimensional Einstein-Gauss-Bonnet (4DEGB) gravity is proposed as a singular limit of the higher-dimensional EGB gravity with a rescaled coupling constant. Follow-up work i…
Revisiting scalar and tensor perturbations in a nonlocal gravity
S. X. Tian, Zong-Hong Zhu
Nonlocal RT gravity is a successful modified gravity theory, which not only explains the late-time cosmic acceleration but also behaves well in the solar system. Previous analysis…
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…
Scalar-tensor nonlocal gravity
Shuxun Tian
In order to explain the late-time cosmological acceleration, we propose a new pure geometric gravity based on Deser-Woodard theory, in which the expansion of a matter-dominated uni…
4G: Pure fourth-order gravity
Shuxun Tian
Einstein field equations are second-order differential equations. In this paper, we propose a new gravity theory with pure fourth-order field equations, which we call 4G for brevit…
Analytic Solution to Geodesic Equations in Lemaître-Tolman-Bondi Metric
Nieng Tian
In this paper, we use the Taylor expansion method to solve the LTB metric.