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Many body gravity and the bullet cluster

S. Ganesh

TL;DR

The paper develops Many Body Gravity (MBG), a gravity theory that ties thermal gradients to spacetime curvature through a 5-D space-time-temperature metric and a partially thermalized stress tensor governed by an equilibration parameter $k$. In the weak-field spherical regime, MBG yields a modified Poisson-like equation $ abla^2 φ = 4πGρ - rac{k c^2}{2} φ abla^2(1/φ)$, and argues that negative $k$ produces physically meaningful galactic dynamics; the inverse-temperature function $s$ scales as $s ightarrow 1/(β_0⟨E_{cl}⟩)$, leading to $ ext{HB relation}$ with $s∝1/φ$. To test MBG, the authors model the Bullet Cluster with a 3-D gas distribution around two BCGs, compute the MBG effective mass density $ ho_{eff}$, and show that the angular component of $ ho_{eff}$ reproduces the observed weak-lensing map $ ilde κ$ without invoking dark matter. The results suggest MBG can account for multiple astrophysical phenomena (galactic rotation curves, RAR, WBS, bullet-cluster lensing) within a unified thermal-geometry framework, though further work is needed to explore thermal geometric effects and multi-component equilibration scenarios.

Abstract

Many body gravity (MBG) is an alternate theory of gravity, which has been able to explain the galaxy rotation curves, the radial acceleration relation (RAR) and the wide binary stars (WBS). The genesis of MBG is a novel theory, which models systems with thermal gradients, by recasting the variation in the temperature as a variation in the metric. Merging the above concept with Einstein's gravity, leads to the theory of thermal gravity in 5-D space-time-temperature. Thermal gravity when generalized for partially thermalized systems, results in the theory of many body gravity. The bullet cluster is supposed to be a smoking gun evidence for the presence of dark matter. However, this work demonstrates that the MBG theory can explain the weak gravitational lensing effect of the bullet cluster, without the need for yet undiscovered baryonic matter or dark matter.

Many body gravity and the bullet cluster

TL;DR

The paper develops Many Body Gravity (MBG), a gravity theory that ties thermal gradients to spacetime curvature through a 5-D space-time-temperature metric and a partially thermalized stress tensor governed by an equilibration parameter . In the weak-field spherical regime, MBG yields a modified Poisson-like equation , and argues that negative produces physically meaningful galactic dynamics; the inverse-temperature function scales as , leading to with . To test MBG, the authors model the Bullet Cluster with a 3-D gas distribution around two BCGs, compute the MBG effective mass density , and show that the angular component of reproduces the observed weak-lensing map without invoking dark matter. The results suggest MBG can account for multiple astrophysical phenomena (galactic rotation curves, RAR, WBS, bullet-cluster lensing) within a unified thermal-geometry framework, though further work is needed to explore thermal geometric effects and multi-component equilibration scenarios.

Abstract

Many body gravity (MBG) is an alternate theory of gravity, which has been able to explain the galaxy rotation curves, the radial acceleration relation (RAR) and the wide binary stars (WBS). The genesis of MBG is a novel theory, which models systems with thermal gradients, by recasting the variation in the temperature as a variation in the metric. Merging the above concept with Einstein's gravity, leads to the theory of thermal gravity in 5-D space-time-temperature. Thermal gravity when generalized for partially thermalized systems, results in the theory of many body gravity. The bullet cluster is supposed to be a smoking gun evidence for the presence of dark matter. However, this work demonstrates that the MBG theory can explain the weak gravitational lensing effect of the bullet cluster, without the need for yet undiscovered baryonic matter or dark matter.
Paper Structure (12 sections, 56 equations, 5 figures, 1 table)

This paper contains 12 sections, 56 equations, 5 figures, 1 table.

Table of Contents

  1. Introduction
  2. The MBG theory
  3. An overview of the MBG theory
  4. Spherical symmetric case
  5. Interpretation of $k$
  6. Modeling of $s$
  7. Negative $k$ and qualitative analysis
  8. Bullet Cluster: A proof of concept
  9. Modeling of the system
  10. Simulation results
  11. Conclusion
  12. The gas density

Figures (5)

  • Figure 1: Bullet cluster: Superimposition of the surface mass due to the effective mass, $\rho_{eff}^{angular}$ from MBG (red) upon the $\kappa$ map from weak gravitational lensing (blue) bullet4.
  • Figure 2: Bullet cluster: Contours of the surface mass due to the effective mass, $\rho_{eff}^{angular}$, from MBG (black) and the contours of the $\kappa$ map from weak gravitational lensing (red) bullet4.
  • Figure 3: Bullet cluster: Cross sectional view of Fig. \ref{['fig:bullet_3D']}. Comparison between the surface mass due to the effective mass, $\rho_{eff}^{angular}$, from MBG (black) and the $\kappa$ map from weak gravitational lensing (red) bullet4.
  • Figure 4: Radial effective mass due to Bullet cluster: Cross sectional view of the effective mass in the radial direction. Comparison between the surface mass due to the effective mass, $\rho_{eff}^{radial}$, from MBG (black) in the radial direction and the $\kappa$ map from weak gravitational lensing (red) bullet4.
  • Figure 5: The pressure at $r$ should support the column of gas above it, contained in the solid angle $d\Omega$