The long-standing problem of the maximum mass that can be achieved by the compact objects,with clear implications for the equation of state of matter above the nuclear saturation density(see ref.[1]and references ther...The long-standing problem of the maximum mass that can be achieved by the compact objects,with clear implications for the equation of state of matter above the nuclear saturation density(see ref.[1]and references therein),is receiving a new twist with the latest data from binary systems and NS-NS merging events.Long ago,double neutron stars systems(DNS)data installed the idea of a"canonical"mass of^1.4 M_⊙,but later work provided evidence for heavier objects with increasing degree of confidence,and it became clear that at least a second"mass scale"had to be present[2].展开更多
We propose a new exponential shape function in wormhole geometry within modified gravity.The energy conditions and the equation-of-state parameter are obtained.The radial and tangential null energy conditions,and also...We propose a new exponential shape function in wormhole geometry within modified gravity.The energy conditions and the equation-of-state parameter are obtained.The radial and tangential null energy conditions,and also the weak energy condition are validated,which indicates the absence of exotic matter due to modified gravity allied with such a new proposal.展开更多
We revisit in this work a model for repeating Fast Radio Bursts based of the release of energy provoked by the magnetic field dynamics affecting a magnetar’s crust.We address the basics of such a model by solving the...We revisit in this work a model for repeating Fast Radio Bursts based of the release of energy provoked by the magnetic field dynamics affecting a magnetar’s crust.We address the basics of such a model by solving the propagation of the perturbation approximately,and quantify the energetics and the radiation by bunches of charges in the so-called charge starved region in the magnetosphere.The(almost)simultaneous emission of newly detected X-rays from SGR 1935+2154 is tentatively associated with a reconnection behind the propagation.The strength of f-mode gravitational radiation excited by the event is quantified,and more detailed studies of the nonlinear(spiky)soliton solutions are suggested.展开更多
文摘The long-standing problem of the maximum mass that can be achieved by the compact objects,with clear implications for the equation of state of matter above the nuclear saturation density(see ref.[1]and references therein),is receiving a new twist with the latest data from binary systems and NS-NS merging events.Long ago,double neutron stars systems(DNS)data installed the idea of a"canonical"mass of^1.4 M_⊙,but later work provided evidence for heavier objects with increasing degree of confidence,and it became clear that at least a second"mass scale"had to be present[2].
基金Supported by the Sao Paulo Research Foundation(FAPESP)under Grant No 2018/20689-7
文摘We propose a new exponential shape function in wormhole geometry within modified gravity.The energy conditions and the equation-of-state parameter are obtained.The radial and tangential null energy conditions,and also the weak energy condition are validated,which indicates the absence of exotic matter due to modified gravity allied with such a new proposal.
基金financial support.J.E.H.has been supported by the CNPq Agency(Brazil)the FAPESP foundation(S?o Paulo,Brazil)。
文摘We revisit in this work a model for repeating Fast Radio Bursts based of the release of energy provoked by the magnetic field dynamics affecting a magnetar’s crust.We address the basics of such a model by solving the propagation of the perturbation approximately,and quantify the energetics and the radiation by bunches of charges in the so-called charge starved region in the magnetosphere.The(almost)simultaneous emission of newly detected X-rays from SGR 1935+2154 is tentatively associated with a reconnection behind the propagation.The strength of f-mode gravitational radiation excited by the event is quantified,and more detailed studies of the nonlinear(spiky)soliton solutions are suggested.
