489 citations · 1.5k across the 45 of their papers we have counts for
45 papers
Photon rings and shadows of black holes with non-minimal couplings between curvature and electromagnetic field
Zhixiang Yin, Changjun Gao, Yun-Long Zhang
We investigate black holes with non-minimal couplings between the electromagnetic field and spacetime curvature, focusing on their event horizons, shadows, and photon rings. Such c…
The metric of general rotating spacetimes
Changjun Gao
We propose the metric for general rotating spacetimes. These spacetimes are stationary, axially symmetric and spatially asymptotically flat. They can be the spacetimes outside of r…
How to accomplish inflation and a constant dark energy density
Changjun Gao
It is commonly assumed that the Lagrangian of multi-field theories of gravity contains the sum of kinetic terms of scalar fields. However, we propose here the Lagrangian contains n…
On black holes with scalar hairs
Changjun Gao, Jianhui Qiu
By using the Taylor series method and the solution-generating method, we construct exact black hole solutions with minimally coupled scalar field. We find that the black hole solut…
New understanding of Majumdar-Papapetrou and Perjés-Israel-Wilson solutions
Changjun Gao
Hartle and Hawking have shown that, except for the case of only point monopoles as sources, both the Majumdar-Papapetrou and the Perjés-Israel-Wilson solutions have naked singulari…
Extending Bekenstein's theorem in order to search exact solutions of Einstein-Maxwell-conformal-scalar equations
Jianhui Qiu, Changjun Gao
The Bekenstein's theorem allows us to generate a Einstein-conformal scalar solution from a single Einstein-ordinary scalar solution. In this article, we extend this theorem to Eins…