标题： 由相对论性火球驱动的伽马射线暴的单极引力波 显示英文标题

标题： Monopole gravitational waves from relativistic fireballs driving gamma-ray bursts

摘要： 爱因斯坦的广义相对论预测，压力（一般应力）在产生引力方面与能量密度起着相似的作用。 引力场的源，即主动引力质量密度，有时被称为惠特克质量密度，是不守恒的，因此其变化可以以单极引力波的形式传播。 这种波只能由具有变化引力质量的天体物理源产生。 在这里我们展示，相对论火球——在伽马射线暴现象建模中考虑的——很可能从具有变化惠特克质量的高压等离子体中辐射单极引力波。 此外，前身天体初始质量-能量的大量喷射也有助于单极引力辐射。 我们将单极波识别为爱丁顿分类中的h^11+h^22波，它们与由无质量场携带的能量一起沿z方向传播。 我们证明单极波满足爱因斯坦方程，并且具有无质量场的共同应力-能量张量。 单极波的偏振模式为Phi_22，即这些是垂直波，仅引起测试粒子圆的半径变化（呼吸模式）。 讨论了单极引力波的天文学意义。 显示英文摘要

摘要： Einstein's general relativity predicts that pressure, in general stresses, play a similar role to energy density in generating gravity. The source of gravitational field, the active gravitational mass density, sometimes referred to as Whittaker's mass density, is not conserved, hence its changes can propagate as monopole gravitational waves. Such waves can be generated only by astrophysical sources with varying gravitational mass. Here we show that relativistic fireballs, considered in modelling gamma-ray burst phenomena, are likely to radiate monopole gravitational waves from high-pressure plasma with varying Whittaker's mass. Also, ejection of a significant amount of initial mass-energy of the progenitor contributes to the monopole gravitational radiation. We identify monopole waves with h^11+h^22 waves of Eddington's classification which propagate (in the z-direction) together with the energy carried by massless fields. We show that the monopole waves satisfy Einstein's equations, with a common stress-energy tensor for massless fields. The polarization mode of monopole waves is Phi_22, i.e. these are perpendicular waves which induce changes of the radius of a circle of test particles only (breathing mode). The astrophysical importance of monopole gravitational waves is discussed.