0
votes
0answers
15 views

Instabilities in the CDMT

Could anyone explain or refer to references on why the CDMT f(R) gravity model suffers from Instabilities any why the sign of ${\mu}^{4}$ matters.
0
votes
1answer
37 views

gravity cancelling dark energy

Say there were 2 objects with certain masses (e.g. $m_1$ and $m_2$). If they were close together gravity would attract the 2 objects. If they were a large distance apart the expansion of the universe ...
1
vote
1answer
36 views

Gravity force and dark energy [duplicate]

If gravity is a fundamental force which bends spacetime and dark energy is energy which stretches spacetime, what is the difference between the terms force and energy?
0
votes
0answers
33 views

Is Dark Energy Pushing Us Or Pulling Us? [duplicate]

This may seem silly, but how do they know that the effects we are seeing from dark energy, (which we only assume must be there due to observed acceleration), are not from gravity pulling us out from ...
1
vote
0answers
49 views

Object that causes spacetime to expand?

Is there any thing that will cause spacetime to expand, so that particles are pushed away from them rather than pulled towards it. I know things such as black holes and planets causes dips and curve ...
0
votes
0answers
98 views

Repulsive forces at large distances

I'm currently writing a 3D $n$-body simulator (similar to what you see here to simulate the evolution of a system of n particles under the force of gravity. It works fine for "smaller" scale ...
2
votes
3answers
286 views

Theory that gets rid of dark matter/energy

Is there any physics theory that either groups together gravity and dark energy/dark matter or eliminates dark energy/dark matter by modifying standard understanding of gravity or any force? If so, ...
4
votes
2answers
544 views

How much light is there in space and how heavy is it?

Our night sky is filled with stars. On a dark night a significant fraction of the sky is light. This light, we are told, has been in transit for many millions of years. There must therefore be quite a ...
3
votes
1answer
416 views

Gravitational waves as dark energy?

Is the energy carried by gravitational radiation a viable candidate for $\Lambda$ / dark energy?
1
vote
1answer
21 views

Could dark energy be linked to dark flow?

I couldn't find any other questions regarding dark flow on Wikipedia, so I'm curious. As far as I can tell, dark energy's existence seems to be hard to explain. Since there may be a couple of ideas ...
4
votes
4answers
199 views

Could dark energy be the effect of gravity at great distances?

This may be a silly question, but is it possible that dark energy and gravity are related to each other? Space-time is deformed everywhere in space by objects with mass. The more massive the object, ...
21
votes
3answers
761 views

Are modified theories of gravity credible?

I'm a statistician with a little training in physics and would just like to know the general consensus on a few things. I'm reading a book by John Moffat which basically tries to state how GR makes ...