Paul Pritha, Clarkson Chris, Maartens Roy
Astronomy Unit, School of Physical and Chemical Sciences, <a href="https://ror.org/026zzn846">Queen Mary University of London</a>, London E1 4NS, United Kingdom.
Department of Physics and Astronomy, <a href="https://ror.org/00h2vm590">University of the Western Cape</a>, Cape Town 7535, South Africa.
Phys Rev Lett. 2024 Sep 20;133(12):121001. doi: 10.1103/PhysRevLett.133.121001.
Recent measurements of the four-point correlation function in large-scale galaxy surveys have found apparent evidence of parity violation in the distribution of galaxies. This cannot happen via dynamical gravitational effects in general relativity. If such a violation arose from physics in the early Universe it could indicate important new physics beyond the standard model, and would be at odds with most models of inflation. It is therefore now timely to consider the galaxy trispectrum in more detail. While the intrinsic four-point correlation function, or equivalently the trispectrum, its Fourier counterpart, is parity invariant, the observed trispectrum must take redshift-space distortions into account. Although the standard Newtonian correction also respects parity invariance, we show that subleading relativistic corrections do not. We demonstrate that these can be significant at intermediate linear scales and are dominant over the Newtonian parity-invariant part around the equality scale and above. Therefore when observing the galaxy four-point correlation function, we should expect to detect parity violation on large scales.
近期在大规模星系巡天中对四点相关函数的测量发现，星系分布中存在明显的宇称破缺迹象。在广义相对论中，这一般不会通过动力学引力效应发生。如果这种破缺源于早期宇宙的物理过程，那么它可能预示着超出标准模型的重要新物理，并且与大多数暴胀模型不一致。因此，现在是时候更详细地考虑星系三谱了。虽然固有四点相关函数，或者等效地说它的傅里叶对应物三谱，是宇称不变的，但观测到的三谱必须考虑红移空间畸变。尽管标准牛顿修正也保持宇称不变性，但我们表明次主导相对论修正并非如此。我们证明，这些修正在中等线性尺度上可能很显著，并且在相等尺度及以上比牛顿宇称不变部分占主导。所以在观测星系四点相关函数时，我们应该预期在大尺度上检测到宇称破缺。
