如何用引力波限制宇宙学参数?

限制宇宙学参数,要先给出观测值和对应的红移。简单说,比如使用超新星中的距离模数u(z); BAO数据中的距离参数A(z)…

对于引力波,需要的是光度距离和对应的红移。

所以问题变为,如何从引力波中独立得到红移和光度距离?

1.如何得到光度距离

通过引力波信号的相位测量得到chirp mass,再通过chirp mass和振幅得到光度距离。(通过多个偏振得到inclination angle,可以提高光度距离的准确度)

什么是振幅?

GW’s can be thought of as a longitudinal ripple in space that travels at the speed of light. These ripples occur when two massive objects collide and coalesce into a singular, more massive object, causing the distance between two points in space to change periodically according to the frequency of the signal. The amount of separation between two points is referred to as the strain of the gravitational wave, which is also the amplitude of the GW

2.如何得到红移

1)通过同时发出的电磁波判断。但是黑洞 -黑洞合并不会放出电磁波。

2)通过位置估计碰撞发生在什么星系,那么红移就是星系的红移。

 

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