Nonlocal Gravitomagnetism

Characteristics of Effective Dark Matter in Nonlocal Gravity

Nonlocal gravity (NLG) is a classical nonlocal generalization of Einstein's theory of gravitation that has been constructed in close analogy with the nonlocal electrodynamics of media. According to NLG, what appears as dark matter in astrophysics and cosmology is in reality the nonlocal aspect of the universal gravitational interaction. We focus here on two main features of the effective dark matter in NLG, namely, (a) the density of effective dark matter in NLG is always finite and therefore cusp-free, and (b) there is less effective dark matter in dwarf galaxies than is generally assumed in …

Dynamical Friction in Nonlocal Gravity

We study dynamical friction in the Newtonian regime of nonlocal gravity (NLG), which is a classical nonlocal generalization of Einstein's theory of gravitation. The nonlocal aspect of NLG simulates dark matter. The attributes of the resulting effective dark matter are described and the main physical predictions of nonlocal gravity, which has a characteristic lengthscale of order 1 kpc, for galactic dynamics are presented. Within the framework of NLG, we derive the analogue of Chandrasekhar's formula for dynamical friction. The astrophysical implications of the results for the apparent rotation…

Nonlocal Gravity: Fundamental Tetrads and Constitutive Relations

Nonlocal gravity (NLG) is a classical nonlocal generalization of Einstein's theory of gravitation based on a certain analogy with the nonlocal electrodynamics of media. The history dependence enters NLG through a constitutive relation involving a causal kernel that should ultimately be determined via observational data. The purpose of this paper is to reformulate nonlocal gravity such that the nonlocal aspect of the constitutive relation directly connects measurable quantities as in the nonlocal electrodynamics of media. The resulting constitutive relation turns out to coincide with the recent…

Nonlocal Gravity: Modification of Newtonian Gravitational Force in the Solar System

Nonlocal gravity (NLG) is a classical nonlocal generalization of Einstein's theory of gravitation developed in close analogy with the nonlocal electrodynamics of media. It appears that the nonlocal aspect of the universal gravitational interaction could simulate dark matter. Within the Newtonian regime of NLG, we investigate the deviation of the gravitational force from the Newtonian inverse square law as a consequence of the existence of the effective dark matter. In particular, we work out the magnitude of this deviation in the solar system out to 100 astronomical units. Moreover, we give an…

Evolution of spiral galaxies in nonlocal gravity

We study the evolution of simulated disk galaxies in the context of a nonlocal theory of gravity. In this theory the appearance of the dark matter problem in cosmology and astrophysics is a manifestation of the nonlocality of the gravitational interaction. Using high-resolution N-body simulations, we investigate the dynamical evolution of disk galaxies and compare the result with the standard dark matter viewpoint. Specifically, we construct two exponential galaxy models, one in nonlocal gravity (NLG) and the other surrounded by a Plummer dark matter halo. Both systems start from the same bary…

星系盘的垂直结构：非局域引力与暗物质的对比

The vertical structure of galactic discs: nonlocal gravity versus dark matter

本研究通过高分辨率N体模拟与解析推导，对比了非局域引力理论与标准暗物质模型下星系盘的垂直弯曲不稳定性，发现二者不稳定区域存在差异，为区分两种引力理论提供了新依据。