82 citations · 184 across the 5 of their papers we have counts for
5 papers
The age problem in CDM model
Rong-Jia Yang, Shuang Nan Zhang
The age problem in the CDM model is re-examined. We define the elapsed time of an object is its age plus the age of the Universe when it was born. Therefore in any cosmology…
Cosmological evolution of interacting phantom (quintessence) model in Loop Quantum Gravity
Puxun Wu, Shuang Nan Zhang
The dynamics of interacting dark energy model in loop quantum cosmology (LQC) is studied in this paper. The dark energy has a constant equation of state and interacts with da…
Hardness Ratio Estimation in Low Counting X-ray Photometry
Y. K. Jin, S. N. Zhang, J. F. Wu
Hardness ratios are commonly used in X-ray photometry to indicate spectral properties roughly. It is usually defined as the ratio of counts in two different wavebands. This definit…
Multiwavelength Observations of the BL Lacertae Object PKS 2155-304 with XMM-Newton
Y. H. Zhang, J. M. Bai, S. N. Zhang +3
The optical-UV and X-ray instruments on-board XMM-Ndewton provide an excellent opportunity to perform simultaneous observations of violently variable objects over a broad wavelengt…
Higher Dimensional Reissner-Nordström-FRW metric
Chang Jun Gao, Shuang Nan Zhang
By inspecting some known solutions to Einstein equations, we present the metric of higher dimensional Reissner-Nordstrm black hole in the background of Friedman-Robertson…