Anomalous contribution to galactic rotation curves due to stochastic s

In summary, the paper discusses how stochastic processes, particularly the presence of small-scale structures and irregularities in dark matter distribution, can lead to anomalous contributions in galactic rotation curves. These contributions may help explain discrepancies observed between the predicted and measured rotational velocities of galaxies, suggesting that variations in dark matter density can significantly influence galactic dynamics. The findings highlight the importance of considering stochastic effects in cosmological models to better understand galaxy formation and behavior.
  • #1
kodama
1,026
139
TL;DR Summary
stochastic cosmological constant can explain galactic rotation curves without needing to evoke dark matter
Anomalous contribution to galactic rotation curves due to stochastic spacetime
Jonathan Oppenheim, Andrea Russo
Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics of Galaxies (astro-ph.GA); High Energy Physics - Theory (hep-th)


We consider a proposed alternative to quantum gravity, in which the spacetime metric is treated as classical, even while matter fields remain quantum. Consistency of the theory necessarily requires that the metric evolve stochastically. Here, we show that this stochastic behaviour leads to a modification of general relativity at low accelerations.
In the low acceleration regime, the variance in the acceleration produced by the gravitational field is high in comparison to that produced by the Newtonian potential, and acts as an entropic force, causing a deviation from Einstein's theory of general relativity. We show that in this "diffusion regime", the entropic force acts from a gravitational point of view, as if it were a contribution to the matter distribution.
We compute how this modifies the expectation value of the metric via the path integral formalism, and find that an entropic force driven by a stochastic cosmological constant can explain galactic rotation curves without needing to evoke dark matter. We caution that a greater understanding of this effect is needed before conclusions can be drawn, most likely through numerical simulations, and provide a template for computing the deviation from general relativity which serves as an experimental signature of the Brownian motion of spacetime. arXiv:2402.19459 [pdf, other]

another way to explain MOND in comparison to that produced by Deur self interactions with GR

how plausible ?
 
Last edited:
Physics news on Phys.org
  • #2
Do you have a link to the paper?
 
  • #3
  • Like
Likes Drakkith

FAQ: Anomalous contribution to galactic rotation curves due to stochastic s

What is the anomalous contribution to galactic rotation curves?

The anomalous contribution to galactic rotation curves refers to the unexpected behavior observed in the rotation speeds of stars and gas in galaxies, particularly at large distances from the galactic center. Instead of decreasing as predicted by Newtonian dynamics and the visible mass distribution, rotation speeds tend to remain flat or even rise, suggesting the presence of additional, unseen mass or modifications to gravitational theory.

What role do stochastic processes play in this phenomenon?

Stochastic processes can introduce random fluctuations in the distribution and motion of matter within galaxies. These processes may affect the dynamics of dark matter or baryonic matter, leading to variations in gravitational effects that could account for the anomalous rotation curves observed in some galaxies.

How does this relate to dark matter theories?

This phenomenon is often explained by dark matter theories, which posit the existence of a non-luminous form of matter that exerts gravitational influence. The anomalous rotation curves suggest that dark matter is distributed in a way that is not solely dependent on visible matter, and stochastic contributions may play a role in shaping the overall dark matter profile in galaxies.

Can the anomalous contribution be measured or observed directly?

While the anomalous contribution itself cannot be observed directly, its effects can be inferred through precise measurements of galactic rotation curves. Observations from telescopes and other instruments allow scientists to map the velocities of stars and gas at various distances from the galactic center, helping to identify discrepancies between expected and observed dynamics.

What are the implications of understanding this contribution for cosmology?

Understanding the anomalous contribution to galactic rotation curves has significant implications for cosmology, as it challenges existing models of galaxy formation and evolution. It may lead to new insights into the nature of dark matter, the structure of the universe, and the fundamental laws of physics, potentially guiding future research and theoretical developments in astrophysics.

Similar threads

I Seifert -Solutions of Einstein's equations give flat galactic rotation curves
Replies
14
Views
2K
I Deur Gravitational self-interaction Doesn't Explain Galaxy Rotation Curves
3
Replies
72
Views
8K
I Is this derivation of MOND from General Relativity plausible?
Replies
1
Views
922
I Two recent tests of loop quantum gravity theory
Replies
15
Views
3K
I Evidence of Strong Equivalence Principle Violations?
Replies
3
Views
2K
I Ads/CFT and Ashtekar variables or spinfoam
Replies
7
Views
2K
A LQG Legend Writes Paper Claiming GR Explains Dark Matter Phenomena
8
Replies
264
Views
19K
I Can magnetic fields explain anomalous galaxy rotation curves?
Replies
2
Views
1K
I Noncommutative geometry and asymptotic safe gravity and MOND
Replies
3
Views
2K
I MOND from MacDowell-Mansouri geometrical formulation
Replies
19
Views
3K

Hot Threads

Recent Insights

Back
Top