Toward Gravitational Lensing in Modified Theories of Gravity

Abstract

In this study, we investigate gravitational lensing within modified gravity frameworks, focusing on the Hu-Sawicki $f(R)$ and normal branch Dvali-Gabadadze-Porrati (nDGP) models, and we compare these results with those obtained from general relativity (GR). Our results reveal that both modified gravity models consistently enhance key lensing parameters relative to GR, including the Einstein radius, lensing optical depth, and time delays. Notably, we find that the Hu-Sawicki $f(R)$ and nDGP models yield significantly larger Einstein radii and higher lensing probabilities, especially at greater redshifts, indicating an increased likelihood of lensing events under modified gravity. Our analysis of time delays further shows that the broader mass distributions in these frameworks lead to pronounced differences in high-mass lens systems, providing potential observational markers of modified gravity. Additionally, we observe amplified magnification factors in wave optics regimes, highlighting the potential for gravitational wave (GW) lensing to differentiate modified gravity effects from GR predictions. Through these findings, we propose modified gravity theories as compelling alternatives to GR in explaining cosmic phenomena, with promising implications for future high-precision gravitational lensing surveys.

16 Pages; 6 Figures, Fixed some typos

References in corpus (19)

• f(R,T) gravity
• Models of f(R) Cosmic Acceleration that Evade Solar-System Tests
• f(R) Gravity and Chameleon Theories
• Stability of Cosmological Solution in f(R) Models of Gravity
• A Highly Magnified Star at Redshift 6.2
• The finite source size effect and the wave optics in gravitational lensing
• Strongly Lensed Transient Sources: A Review
• A review on analytical studies in Gravitational Lensing
• A high precision semi-analytic mass function
• A Geometrical Approach to Strong Gravitational Lensing in f(R) Gravity
• A general framework to test gravity using galaxy clusters II: A universal model for the halo concentration in $f(R)$ gravity
• Cosmology with Hu-Sawicki gravity in Palatini Formalism
• A general framework to test gravity using galaxy clusters IV: Cluster and halo properties in DGP gravity
• Prompt cusp formation from the gravitational collapse of peaks in the initial cosmological density field
• Gravitational Lensing in Modified Gravity: A case study for Fast Radio Bursts
• Compact Binary Merger Rate in Dark-Matter Spikes
• On the effect of angular momentum on the prompt cusp formation via the gravitational collapse
• Light bending and gravitational lensing in Brans-Dicke theory
• A comprehensive analysis of the compact phase space for Hu-Sawicki $f(R)$ dark energy models including spatial curvature