Matter Loops Corrected Modified Gravity in Palatini Formulation

作     者：MENG Xin-He WANG Peng 

作者机构：Department of Physics Nankai University Tianjin 300071 China Department of Physics and SLAC Stanford University California USA BK21 Division of Advanced Research and Education in Physics Department of Physics Hanyang University Seoul 133 791 Korea 

出 版 物：《Communications in Theoretical Physics》 (理论物理通讯（英文版）)

年 卷 期：2008年第50卷第7期

页      面：275-278页

核心收录：

学科分类：08[工学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：National Natural Science Foundation of China under Grant No.10675062 the Second Stage Brain Korea 21 Program in Hanyang University 

主　　题：modified gravity accelerated cosmic expansion loop correction and dark energy 

摘      要：Recently,corrections to the standard Einstein Hilbert action were proposed to explain the current cosmicacceleration in stead of introducing dark *** the Palatini formulation of those modified gravity models,thereis an important observation due to Arkani Hamed:matter loops will give rise to a correction to the modified gravityaction proportional to the Ricci scalar of the *** the presence of such a term,we show that the current formsof modified gravity models in Palatini formulation,specifically,the 1/R gravity and in R gravity,will have *** we study the possible instabilities due to the presence of phantom *** show that the strong instability inthe metric formulation of 1/R gravity indicated by Dolgov and Kawasaki will not appear and the decay timescales forthe phantom fields may be long enough for the theories to make sense as effective field *** the other hand,if wechange the sign of the modification terms to eliminate the phantoms,some other inconsistencies will arise for the variousversions of the modified gravity ***,we comment on the universal property of the Palatini formulation ofthe matter loops corrected modified gravity models and its implications.