This website requires JavaScript.

# Equation of state for Buchdahl star and black hole

Dec 2022

It turns out that the Buchdahl star, the most compact object without horizon,is defined by the potential $\Phi(R) = 4/9$ and black hole by $\Phi(R) = 1/2$,where $\Phi(R) = (MR-Q^2/2R)/(R^2+a^2)$ for the Kerr-Newman charged androtating object. Equivalently in terms of gravitational and non-gravitationalenergy, the former is defined when gravitational energy is half ofnon-gravitational energy while the latter when the two are equal. In thisletter we wish to point out that the latter characterization implies that theBuchdahl star is a Virial star as its equilibrium is maintained by averagekinetic energy being half of potential energy, and consequently the equation ofstate $p= \frac{1}{2} \rho$ and sound velocity, $v_s^2 = 1/2$. Similarly thiswould predict an equation of state for black hole $p = \rho$ and $v_s^2=1$.

Q1论文试图解决什么问题？
Q2这是否是一个新的问题？
Q3这篇文章要验证一个什么科学假设？
0