Full-sky lensing shear at second order

Journal Article · Thu Apr 15 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.083002· OSTI ID:21409550

Bernardeau, Francis; Bonvin, Camille; Vernizzi, Filippo ^[1]

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1. CEA, Institut de Physique Theorique, 91191 Gif-sur-Yvette cedex (France)

We compute the reduced cosmic shear up to second order in the gravitational potential without relying on the small-angle or thin-lens approximation. This is obtained by solving the Sachs equation which describes the deformation of the infinitesimal cross section of a light bundle in the optical limit, and maps galaxy intrinsic shapes into their angular images. The calculation is done in the Poisson gauge without a specific matter content, including vector and tensor perturbations generated at second order and taking account of the inhomogeneities of a fixed redshift source plane. Our final result is expressed in terms of spin-2 operators on the sphere and is valid on the full sky. Beside the well-known lens-lens and Born corrections that dominate on small angular scales, we find new nonlinear couplings. These are a purely general relativistic intrinsic contribution, a coupling between the gravitational potential at the source with the lens, couplings between the time delay with the lens and between two photon deflections, as well as nonlinear couplings due to the second-order vector and tensor components. The inhomogeneity in the redshift of the source induces a coupling between the photon redshift with the lens. All these corrections become important on large angular scales and should thus be included when computing higher-order observables such as the bispectrum, in full or partially full-sky surveys.

• OSTI ID: 21409550
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 8; Other Information: DOI: 10.1103/PhysRevD.81.083002; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
APPROXIMATIONS
COMPUTERIZED SIMULATION
CORRECTIONS
COUPLING
CROSS SECTIONS
DEFORMATION
DISTURBANCES
EQUATIONS
GALAXIES
GRAVITATIONAL LENSES
NONLINEAR PROBLEMS
PERTURBATION THEORY
PHOTONS
RED SHIFT
RELATIVISTIC RANGE
SPIN
TIME DELAY
ANGULAR MOMENTUM
BOSONS
CALCULATION METHODS
ELEMENTARY PARTICLES
ENERGY RANGE
LENSES
MASSLESS PARTICLES
PARTICLE PROPERTIES
SIMULATION