摘要
Recently,a de-Sitter epoch has been found in the new model of loop quantum cosmology,which is governed by the scalar constraint with both Euclidean and Lorentz terms.The singularity free bounce in the new LQC model and the emergent cosmology constant strongly suggest that the effective stress-energy tensor induced by quantum corrections must violate the standard energy conditions.In this study,we perform an explicit calculation to analyze the behaviors of specific representative energy conditions,i.e.,average null,strong,and dominant energy conditions.We reveal that the average null energy condition is violated at all times,while the dominant energy condition is violated only at a period around the bounce point.The strong energy condition is violated not only at a period around the bounce point but also in the whole period from the bounce point to the classical phase corresponding to the de Sitter period.Our results will shed some light on the construction of a wormhole and time machine,which usually require exotic matter to violate energy conditions.
作者
Gaoping Long
Yunlong Liu
Xiangdong Zhang
龙高平;刘云龙;张向东(Department of Physics,South China University of Technology,Guangzhou 510641,China;Department of Physics,Beijing Normal University,Beijing 100875,China)
基金
Supported by the National Natural Science Foundation of China(NSFC)(11775082,12047519,11875006,11961131013)
China Postdoctoral Science Foundation(2021M691072)。