On parametrized cold dense matter equation-of-state inference
On parametrized cold dense matter equation-of-state inference
复制标题
参数化冷致密物质状态方程推断
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
A. Watts
中科院分区：
文献类型：
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作者：
T. E. Riley;G. Raaijmakers;A. Watts
限制致密恒星中冷致密物质的状态方程是使用X射线、射电和引力波望远镜进行观测的一个主要科学目标。我们讨论了参数化密物质状态方程的贝叶斯分层推理。特别是，我们概括和检验了文献中的两种推断范例：(I)直接后验状态方程参数估计，条件是观测一组旋转的致密恒星；(Ii)间接参数估计，通过变换外部时空参数(如引力质量和坐标赤道半径)的中间联合后验分布。我们的结论是，前一种范式不仅适用于大规模分析，而且从贝叶斯的角度来看，它是有原则的和灵活的，而后一种范式则不是。贝叶斯先验定义的主题问题成为这两种范式之间差异的症结所在。第二种范式一般只应被认为是利用档案对外部时空参数的后验约束问题的一种定义不明确的方法；我们主张采用另一种方法，将这种信息重新用作近似似然函数。我们还讨论了为什么分段多变状态方程模型的条件很容易违反在外部(时空)和内部(源物质)参数空间之间转换概率密度分布所需的条件。
Constraining the equation of state of cold dense matter in compact stars is a major science goal for observing programmes being conducted using X-ray, radio, and gravitational wave telescopes. We discuss Bayesian hierarchical inference of parametrized dense matter equations of state. In particular, we generalize and examine two inference paradigms from the literature: (i) direct posterior equation-of-state parameter estimation, conditioned on observations of a set of rotating compact stars; and (ii) indirect parameter estimation, via transformation of an intermediary joint posterior distribution of exterior spacetime parameters (such as gravitational masses and coordinate equatorial radii). We conclude that the former paradigm is not only tractable for large-scale analyses, but is principled and flexible from a Bayesian perspective while the latter paradigm is not. The thematic problem of Bayesian prior definition emerges as the crux of the difference between these paradigms. The second paradigm should in general only be considered as an ill-defined approach to the problem of utilizing archival posterior constraints on exterior spacetime parameters; we advocate for an alternative approach whereby such information is repurposed as an approximative likelihood function. We also discuss why conditioning on a piecewise-polytropic equation-of-state model – currently standard in the field of dense matter study – can easily violate conditions required for transformation of a probability density distribution between spaces of exterior (spacetime) and interior (source matter) parameters.
影响因子：
8.6
作者：
M. Alford;A. Sedrakian
通讯作者：
M. Alford;A. Sedrakian