TY - JOUR
T1 - Nonlinear relativistic corrections to cosmological distances, redshift and gravitational lensing magnification
T2 - I. key results
AU - Umeh, Obinna
AU - Clarkson, Chris
AU - Maartens, Roy
PY - 2014/10/1
Y1 - 2014/10/1
N2 - The next generation of telescopes will usher in an era of precision cosmology, capable of determining the cosmological model to beyond the percent level. For this to be effective, the theoretical model must be understood to at least the same level of precision. A range of subtle relativistic effects remain to be explored theoretically, and offer the potential for probing general relativity in this new regime. We present the distance-redshift relation to second order in cosmological perturbation theory for a general dark energy model. This relation determines the magnification of sources at high precision, as well as redshift space distortions in the mildly non-linear regime. We identify a range of new lensing effects, including: double-integrated and nonlinear-integrated Sachs-Wolfe contributions, transverse Doppler effects, lensing from the induced vector mode and gravitational wave backgrounds, in addition to lensing from the secondorder potential. Modifications to Doppler lensing from redshift space distortions are identified. Finally, we find a new double-coupling between the density fluctuations integrated along the line of sight, and gradients in the density fluctuations coupled to transverse velocities along the line of sight. These can be large and thus offer important new probes of gravitational lensing and general relativity. This paper accompanies paper II (Umeh, Clarkson and Maartens 2014 Class. Quantum Grav. 31 205001), where a comprehensive derivation is given.
AB - The next generation of telescopes will usher in an era of precision cosmology, capable of determining the cosmological model to beyond the percent level. For this to be effective, the theoretical model must be understood to at least the same level of precision. A range of subtle relativistic effects remain to be explored theoretically, and offer the potential for probing general relativity in this new regime. We present the distance-redshift relation to second order in cosmological perturbation theory for a general dark energy model. This relation determines the magnification of sources at high precision, as well as redshift space distortions in the mildly non-linear regime. We identify a range of new lensing effects, including: double-integrated and nonlinear-integrated Sachs-Wolfe contributions, transverse Doppler effects, lensing from the induced vector mode and gravitational wave backgrounds, in addition to lensing from the secondorder potential. Modifications to Doppler lensing from redshift space distortions are identified. Finally, we find a new double-coupling between the density fluctuations integrated along the line of sight, and gradients in the density fluctuations coupled to transverse velocities along the line of sight. These can be large and thus offer important new probes of gravitational lensing and general relativity. This paper accompanies paper II (Umeh, Clarkson and Maartens 2014 Class. Quantum Grav. 31 205001), where a comprehensive derivation is given.
KW - Cosmology
KW - Lensing
KW - Perturbation theory
KW - RCUK
KW - STFC
KW - ST/H002774/1
UR - http://www.scopus.com/inward/record.url?scp=84908168245&partnerID=8YFLogxK
U2 - 10.1088/0264-9381/31/20/202001
DO - 10.1088/0264-9381/31/20/202001
M3 - Article
AN - SCOPUS:84908168245
SN - 0264-9381
VL - 31
SP - 202001
JO - Classical and Quantum Gravity
JF - Classical and Quantum Gravity
IS - 20
M1 - 202001
ER -