A two-dimensional Brans-Dicke star model with exotic matter and dark energy is studied in this paper,the field equation and balance equation are derived at finite temperature,the analytic solutions of these equations ...A two-dimensional Brans-Dicke star model with exotic matter and dark energy is studied in this paper,the field equation and balance equation are derived at finite temperature,the analytic solutions of these equations canbe used to calculate the mass of star.In addition,we find that star's mass has a minimum when matter state parameterγ→0.展开更多
This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density σis positive, while ...This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density σis positive, while the surface pressure is negative, resulting in , thereby signaling a violation of the null energy condition, a necessary condition for holding a wormhole open. For a Morris-Thorne wormhole, matter that violates the null energy condition is referred to as “exotic”. For the thin-shell wormholes in this paper, however, the violation has a physical explanation since it is a direct consequence of the embedding theory in conjunction with the assumption of conformal symmetry. These properties avoid the need to hypothesize the existence of the highly problematical exotic matter.展开更多
In this work,we have explored wormhole(WH)solutions in F(R,L_(m))gravity by assuming the Morris-Thorne WH metric and F(R,Lm)=R/2+(1+γR)L_(m),whereγis the free model parameter.We determined the WH solutions by utiliz...In this work,we have explored wormhole(WH)solutions in F(R,L_(m))gravity by assuming the Morris-Thorne WH metric and F(R,Lm)=R/2+(1+γR)L_(m),whereγis the free model parameter.We determined the WH solutions by utilizing two newly developed shape functions(SF)that satisfy all basic conditions for a WH’s physical validity.We also observe that the null energy condition(NEC)behaves negatively.Finally,for both models,we use the volume integral quantifier(VIQ)and Tolman-Oppenheimer-Volkoff(TOV)equation to determine how much exotic matter is needed near the WH throat and the stability of the WH.The extensive detailed discussions of the matter components have been done via graphical analysis.The obtained WH geometries meet the physically acceptable conditions for a stable wormhole.展开更多
基金Supported by the Natural Science Foundation of Sichuan Education Committee under Grant No.08ZA038
文摘A two-dimensional Brans-Dicke star model with exotic matter and dark energy is studied in this paper,the field equation and balance equation are derived at finite temperature,the analytic solutions of these equations canbe used to calculate the mass of star.In addition,we find that star's mass has a minimum when matter state parameterγ→0.
文摘This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density σis positive, while the surface pressure is negative, resulting in , thereby signaling a violation of the null energy condition, a necessary condition for holding a wormhole open. For a Morris-Thorne wormhole, matter that violates the null energy condition is referred to as “exotic”. For the thin-shell wormholes in this paper, however, the violation has a physical explanation since it is a direct consequence of the embedding theory in conjunction with the assumption of conformal symmetry. These properties avoid the need to hypothesize the existence of the highly problematical exotic matter.
基金S Chaudhary expresses his gratitude to the Central University of Haryana for providing a University Research Fellowship (URF) under the Reg. No. 222019the Department of Mathematics, Central University of Haryanathe University Grant Commission (UGC), New Delhi, India under the NTA Ref. No. 211610000030 for providing financial support
文摘In this work,we have explored wormhole(WH)solutions in F(R,L_(m))gravity by assuming the Morris-Thorne WH metric and F(R,Lm)=R/2+(1+γR)L_(m),whereγis the free model parameter.We determined the WH solutions by utilizing two newly developed shape functions(SF)that satisfy all basic conditions for a WH’s physical validity.We also observe that the null energy condition(NEC)behaves negatively.Finally,for both models,we use the volume integral quantifier(VIQ)and Tolman-Oppenheimer-Volkoff(TOV)equation to determine how much exotic matter is needed near the WH throat and the stability of the WH.The extensive detailed discussions of the matter components have been done via graphical analysis.The obtained WH geometries meet the physically acceptable conditions for a stable wormhole.
