dark-matter's questions - English 1answer

547 dark-matter questions.

Is it true that the predictions from the General Theory of Relativity don’t match the observations of galaxy rotation speeds, and that this then started the search for dark matter? Is it only the ...

I'm curious about this. I saw this: https://www.forbes.com/sites/brucedorminey/2018/07/18/is-time-running-out-on-dark-matter/ and they're suggesting that as direct searches for dark matter more and ...

Is it possible that the dark matter is simply missed variables in the math? I am not a physicist but examples might include: effects of planetary and galaxy rotation, electromagnetic fields, ...

Dark matter is suppose to form large halos of unknown yet type of particle with a specific density density profile. Does the dark matter halo can be viewed as a fluid of particles with density and non-...

Dark matter can be observed at the LHC via a mono-jet signal i.e $pp\rightarrow XX + jet$. These signals can proceed via parton level processes like the mono gluon or mono photon ones. I was ...

One of the models of dark energy uses the Chaplygin gas (in the generalized version it can even provide a unified model of dark energy and dark matter). What is/are the issue/s with respect to the ...

The necessity of dark matter is suspect to me because of two distinct questions: We know that gravitational wells like that of massive stars do in fact slow the light coming from them to some degree. ...

Rotation curves of galaxies seem to require more mass than observed - the conventional solution is the introduction of Dark Matter. Reading some articles on this topic (in particular a recent ...

This is a slightly different variation on an earlier question: In the very early universe, the hot plasma consisted of fixed amount of radiation (photons and neutrinos) and matter (electrons, protons,...

I've read that dark matter's existence is theorized because galaxies spin/clump in a way that would require much more mass than there appears to be. Also that there is gravitational lensing in places ...

IceCube, XENON, etc, keep yielding negative results. If dark matter exists, it doesn't interact with baryonic matter at the energy ranges they can detect. The response is to build even bigger ...

I watched a YouTube post on a channel that normally has solid information about astronomy (as far as I can tell). But this episode states that (emphasis mine): …talking about the controversial ...

In Dodelson's book, the equation for a scattering process $ a + b \Leftrightarrow c + d $ is given as \begin{align} a^{-3} \frac{\mathrm d (n_a a^3)}{\mathrm d t}&=-n^{\text{eq}}_a n^{\text{eq}}...

Main question Gravitational redshift for photons are a wellknown phenomena where the electromagnetic radiation is reduced in frequency and thus the wavelenght is increased. The wave–particle ...

There are several cosmological parameters that are more or less of the same order $10^{-60}$ (in Planck unit), namely, inverse of the age of the universe $$ \frac{1}{t_0}, $$ Hubble constant $$ H_0, $...

After freeze-out, the WIMPs departed from chemical equilibrium and till today, it maintains a constant number density. That appears enough to account for the observed relic density. But we also assume ...

If the dark matter halo is stationary related to the arms of the galaxy then tidal effects should slow the galaxy rotation. If it rotates with the normal matter in the galaxy then shouldn't it ...

Background Consider the number changing interactions of the WIMP-type dark matter in the early Universe of the form $$\zeta\zeta\leftrightarrow XX\tag{1}$$ where $\zeta$ is the representative of the ...

For a dark matter of mass $m$, the typical freeze-out temperature is $T$ is usually assumed to be between $\frac{m}{20}-\frac{m}{25}$. But the freeze-out temperature depends upon the annihilation ...

We search for dark matter using direct techniques searching for a recoil of e.g. nobel gases atoms (Xenon1T,...) or indirect techniques (gamma-ray observations of dwarf spheroidal galaxies, the ...

There's more gravitational force in our galaxy (and others) than can be explained by counting stars made of ordinary matter. So why not lots of dark planetary systems (i.e., without stars) made of ...

I'm an astrophysics student and I've been researching this topic and there is one point that keeps eluding me. How did the scientific community realize that there had to be dark matter in the ...

The Higgs field has a nonzero vacuum expectation value which contributes to the energy density of the Universe. Energies contribute to the curvature of spacetime and affected by gravitational ...

Higgs boson, though electrically neutral, can decay to produce a pair of photons i.e., have electromagnetic interactions. See the answer here. Therefore, it appears that making dark matter ...

Can we assign a thermal distribution function to Dark Matter(not necessarily known ones)? Is it possible that they won't even follow thermal distribution function and maybe a function of something ...

The $\Lambda$CDM model assumes collisionless dark matter, so that its pressure $P=0$. But what are the best experimental constraints on $P$? I guess on $P/\rho$ in fact…

I recently attended a talk where the speaker said that it is impossible for us gain information about the history of particles which make up the black hole. i.e we won't know if the black hole was ...

Why is it that in cosmology, everything is treated as a "fluid"? What justifies modelling radiation, matter, etc. as "fluids" (even dark energy??)? When does it break down -- surely at small scales ...

This paper (2010) hypothesizes that Higgs bosons might be absolutely stable, allowing them to serve as a cold dark matter candidate: The Higgs boson is in the backbone of the standard model of ...

According to the $\Lambda$CDM parametrization of the Standard Model of Big Bang cosmology, the universe contains a cosmological constant $\Lambda$ associated with $73\%$ dark energy, $23\%$cold dark ...

If gravitational lensing implies that Dark Matter exerts gravity onto light then why are the stars and regular matter not clustering around Dark Matter?

There have been a number of papers on the astronomically observed 3.5keV line, the most recent being "Searching for the 3.5 keV Line in the Deep Fields with Chandra: The 10 Ms Observations". These ...

I understand DAMA is a dark matter detector but I don't understand how it works, and what it's seeing. They claim to have a seasonal variation in their signal which is supportive of a certain type of ...

I'm trying to make sense on how the upper limits of the cross section of particle dark matter (WIMPs) are computed, like in the figure below. This is taken from an article on dark matter searches. ...

This well-cited paper talks about a minimal renormalizable extension to the Standard Model (SM) to incorporate particle dark matter (DM) into it by adding a real scalar field $S$ which (unlike the ...

Assuming that dark matter is not made of WIMPs (weakly interacting massive particles), but interacts only gravitationally, what would be the possible mechanism giving mass to dark matter particles? If ...

Is there any evidence for dark matter besides just its gravitational effects? What I’m getting at is...why are we so quick to assume it’s any kind of “matter” at all rather than just some unexplained ...

I think I saw in a video that if dark matter wasn't repulsive to dark matter, it would have formed dense massive objects or even black holes which we should have detected. So, could dark matter be ...

What are the papers where the first evidence for dark matter related with the stability of galactic discs, and the orbits of galaxy satellites?

I am by no means a physicist. I lack credentials and formal education. I did however have an interest in theoretical physics when I was younger. This post is to present my thoughts/idea/theory or ...

In most of the papers that I encounter, the mass range for Dark matter is generally taken to be 1-1000 GeV. Is it possible that dark matter is of the order of few MeV? What observation is violated in ...

A major reason for believing in the existence of dark matter is that the stars in the outer regions of galaxies are moving too fast to remain bound to their galaxies, given only the estimated mass of ...

Can light be shifted or stopped by anything other than a solid? I ask because when observing black holes you can see light funneling into the sphere. My thought was that if what’s being pulled into ...

Today, I was watching the Inexplicable Universe with Neil deGrasse Tyson. He spoke about Dark Matter, Dark Energy, and then he spoke about Tachyons. Naively, I thought what if the reason we can't ...

I've been reading/hearing that if the AMS satellite measures a significant flux of anti-helium in cosmic rays, that would be an irrefutable proof of dark matter. I was wondering: Why is that? what is ...

I am a physics student and as far as I know dark matter is beyond the topics included in my grade career. Are there any serious book on the subject? Any serious set of lectures somewhere in Internet?

My (possibly poor) understanding of the argument for Dark Matter's existence is that stars in a large galaxy move more slowly than "they should" (presumably due to either some simplified model of the ...

I'm trying to estimate the local density of dark matter at a given radius, $r=R_0=8\text{kpc}$. I also have values for the core radius, $a=5\text{kpc}$, and circular velocity of the Sun, $v_{\text{...

It's my understanding that the mechanism behind Coronal Heating - why the Corona is so much hotter (> 1,000,000 K) than the surface of the Sun (6,000 K), and the mechanism by which the energy gets ...

I have read these questions and their answers: Dark matter black holes Could Dark Matter form black hole? Does dark matter originate from matter falling into a black hole? following up dark matter ...

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