English

Integrated perturbation theory for cosmological tensor fields. III. Projection effects

Cosmology and Nongalactic Astrophysics 2024-09-23 v3 General Relativity and Quantum Cosmology

Abstract

The integrated perturbation theory (iPT) is a set of methods in nonlinear perturbation theory for the structure formation in the Universe. In Papers I and II [arXiv:2210.10435, arXiv:2210.11085], the basic formalism and technical methods of the iPT for cosmological tensor fields are developed, generalizing the corresponding theory for scalar fields. In previous papers, methods to predict statistical quantities, such as power spectra, correlation functions, etc., of three-dimensional tensor fields are developed based on the iPT. However, observations of tensors, such as angular momenta and shapes of galaxies, etc., are only possible after the three-dimensional tensors are projected onto the two-dimensional sky. In this paper, power spectra and correlation functions of projected two-dimensional tensors are related to those of original three-dimensional tensors, so that one can make predictions for the observable statistics of projected tensor fields from the iPT. The relations are consistently represented on the basis of irreducible decomposition of both two- and three-dimensional tensors.

Keywords

Cite

@article{arxiv.2304.13304,
  title  = {Integrated perturbation theory for cosmological tensor fields. III. Projection effects},
  author = {Takahiko Matsubara},
  journal= {arXiv preprint arXiv:2304.13304},
  year   = {2024}
}

Comments

30 pages, no figure, this paper is the third of a series, the first one is arXiv:2210.10435, the second one is arXiv:2210.11085 and the fourth one is arXiv:2405.09038

R2 v1 2026-06-28T10:18:06.327Z