I know fundamental forces are made up of 4 forces Gravity, Electromagnetic, Strong and Weak forces. Why Dark matter and Dark Energy not part of fundamental forces? Is it because we don't know their sources yet or for some other reasons?
What you call fundamental forces are (with the exception of gravity) the forces we associate with vector particles in the Standard Model of particle physics: electromagnetism (photons), the weak interaction (W and Z bosons) and the strong nuclear force (gluons).
Dark matter and dark energy are not part of the Standard Model, because at the present, we know almost nothing about them other than their gravity and approximate macroscopic equation of state.
Depending on the theory that prevails, these "dark sectors" may introduce new fundamental forces.
For instance, if dark energy turns out to be a pure cosmological constant, then it's not a matter field or force, but a geometric property of spacetime.
Nor is it a new matter field or force if it turns out to be, after all, a manifestation of vacuum energy.
But if it turns out to be related to, say, a new scalar field with a self-interaction potential, that scalar field may very well qualify as a new fundamental force.
Similarly, while dark matter is unlikely to be composed of baryons (i.e., "ordinary" matter) it may turn out to be something that is a relatively straightforward extension of the Standard Model, like sterile neutrinos. If that is the case, there are no new forces. But it may turn out to be a whole new fundamental particle, and it may very well be that those dark matter particles interact with each other through, say, "dark photons"; that would certainly qualify as a new fundamental force.
So the premise of your question is not necessarily valid: there may or may not be new fundamental forces associated with dark matter and dark energy, we just don't know at the present.
We are now certain of the existence of both dark matter and dark energy in the Universe, but we know nothing of their origin or what is sourcing them. There is an abundance of theoretical speculations, but it is the lack of empirical data, beyond the standard 4% we think we know, that seems to be the problem. We need more astronomical observations and high energy physics data to select the right explanation. As of know the traditional concept of dark energy comes from the Lambda cosmological constant in the Einstein field equations, so it is a part of the gravitational force. The dark matter seem to consists of unknown weakly interacting particles that may or may not be a part of the standard model of elementary particles, which describes the other 3 known fundamental forces in Nature. Every other explanation borders with the sci-fi realm.
Hope this helps.
What you call fundamental forces are (with the exception of gravity) the forces we associate with vector particles in the Standard Model of particle physics: electromagnetism (photons), the weak interaction (W and Z bosons) and the strong nuclear force (gluons).
Dark matter and dark energy are not part of the Standard Model, because at the present, we know almost nothing about them other than their gravity and approximate macroscopic equation of state.
Depending on the theory that prevails, these "dark sectors" may introduce new fundamental forces.
For instance, if dark energy turns out to be a pure cosmological constant, then it's not a matter field or force, but a geometric property of spacetime.
Nor is it a new matter field or force if it turns out to be, after all, a manifestation of vacuum energy.
But if it turns out to be related to, say, a new scalar field with a self-interaction potential, that scalar field may very well qualify as a new fundamental force.
Similarly, while dark matter is unlikely to be composed of baryons (i.e., "ordinary" matter) it may turn out to be something that is a relatively straightforward extension of the Standard Model, like sterile neutrinos. If that is the case, there are no new forces. But it may turn out to be a whole new fundamental particle, and it may very well be that those dark matter particles interact with each other through, say, "dark photons"; that would certainly qualify as a new fundamental force.
So the premise of your question is not necessarily valid: there may or may not be new fundamental forces associated with dark matter and dark energy, we just don't know at the present.
Thank you V. T. Toth,
What I understand from your comment, because we cannot be sure about it cause we cannot say it is fundamental force or not. And if it comes out to be new force (using new elementary particles) it can fit in fundamental forces.
Correct me If I inferred wrong.
Regards,
Bhushan Poojary
Dear Bhushan Bhoja Poojary: yes, your understanding is approximately correct. I'd just like to clarify that it's not that dark matter (or dark energy) might itself be a fundamental force, but rather, once we find out the physics behind dark matter (dark energy), this new physics may involve new fundamental forces. Or not. We just don't know yet.
Thank you Mohamed,
Higher dimensions makes sense to me,
Regards,
Bhushan Poojary
Because they are not more than the curvature that manifest the gravitational field.
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