Dark matter Definition and 920 Threads

Are there variations of dark matter concentration on Earth based on months or seasons of the year?

Erebon theory is a novel explanation of dark matter recently invented by Roger Penrose. Erebons are scalar particles of the order of a Planck mass which can only interact gravitationally. When erebons decay, they release their energy as oscillating classical gravitational waves on the order of...

My physics teacher, who dislikes the idea of dark matter, told me that a physicist created an alternative explanation to the phenomena caused by dark matter. Is there something I missed on the news? What is the alternative theory to dark matter and how does it explain 'things' ?

I've been reading several ideas postulated by some researchers using either Dark Matter and or a micro Black Hole as energy sources to power a future spacecraft . 1) using dark matter as fuel to power a spacecraft by taking dark matter into a cavity and shrinking it to critical point using...

Roger Penrose, July 2017. Correlated "noise" in LIGO gravitational wave signals: an implication of Conformal Cyclic Cosmology

Dark energy is still energy so couldn't it also gravitate? The question is how large of a region of space must there be before dark energy could sustain itself at a higher density through self-gravitation? I'm under the impression that dark matter works at a smaller scale than dark energy. Or do...

As I have come to understand it - we have no current means of directly interacting with Dark Matter. We can only observe the gravitational effects that Dark Matter has on Baryonic Matter. My question is: What forms of detection have been attempted and determined to not directly interaction...

Without knowing whether WIMPs or axions or something else are what dark matter is composed of, can we speculate about the vacuum density creating only normal matter, and by what mechanism?

While the subject has been talked about to death by many a researcher, who will discover the first dark matter scientific paper that will prove beyond theory that describes it in detail. The real discoverer will undoubtedly be the hero of physics, astrophysics, and cosmology and be awarded...

Reading some of the recent info on black holes and how they ingest gas matter including stellar material... why doesn't dark matter be absorbed into the black hole and according to the article dark matter is part of black hole formation...

There's a question that's been in my mind for quite a while but I cannot figure out what the answer is. I't probably an ill posed question but I will ask it anyway: 1.- Do we know what the dark-matter statistical distribution in our Universe is (at large scales)? 2.- In case we do, could...

If space is expanding and at the same time speeding up, something must be driving it. It also appears to be self perpetuating, as something cannot continue to expand, speed up and backfill at the same time? Could the driving force be dark matter/energy?

How much tension between recent AMS-02 80 Gev dark matter and Lux-Xenon negative results? Recent results ( Arxiv 1610.03840 and 1704.08258) suggest a WIMP dark matter particle near 80 Gev. See also https://phys.org/news/2017-05-possibility-cosmic-rays-due-dark.html If this particle really...

Is dark matter physics considered a low or high energy physics, and why?

Why is it that dark matter does not inhabit gas clouds, I would have thought that thees gas clouds will some day become a galaxy, so why no Dark Matter?

Hello, I've been reading articles about the OGLE micro-lensing project, which started out looking to find dark matter as 'massive compact objects,' but now seems to have had more success finding exoplanets. Searching the forums here I couldn't find much recent discussion about theories of this...

I recall reading somewhere (I can't remember where) that there is astronomical evidence that dark matter has different densities in different parts of the relatively near parts of the observable universe. Q1. Is this correct? If so, can someone please post a link to a relevant article? The...

Dark Matter was never found, what Modified Gravity theories should we check now?

https://www.sciencedaily.com/releases/2016/12/161219085020.htm http://www.skyandtelescope.com/astronomy-news/no-dark-matter-from-lux-experiment/ I believe that WIMP theory has been the leading contender for dark matter in the past, but the null results from LUX, PandaX, Fermi and LHC would all...

Hello, I have been reading about how Dark Matter particles might possibly be made up of the lightest sterile right handed neutrino. I was wondering, why exactly does the dark matter particle have to decouple from the plasma when it is formed?

Hello, So I am aware that neutrino masses, Baryogengesis/Baryon Asymmetry, and Dark matter cannot be explained by the standard model. However each can be explained by right handed neutrinos. I know that right handed neutrinos show up in many extensions to the standard model, e.g. vMSM (where...

arXiv:1703.05772 [pdf, other] Newly-Discovered Anomalies in Galactic Cosmic Rays: Time for Exotic Scenarios? Mikhail Malkov Comments: Cosmic Rays beyond the Standard Model, San Vito, 2016, this http URL, conference paper Subjects: High Energy Astrophysical Phenomena (astro-ph.HE) Recent...

This suggests to me that the early universe did not contain as much dark matter. Is this correct? If so it might give a clue what D.M actually is? http://www.space.com/36083-dark-matter-minor-ingredient-of-early-galaxies.html

Ordinary Standard Model neutrinos _are_ dark matter particles, in a sense that they have mass, and they only weakly interact with everything else. IIRC they are not considered to be a satisfactory candidate because nearly all neutrinos in the Universe are relativistic, whereas we know that...

ok so this has been on my mind for a while. If the hotter a stars burn or flame the further it goes on the spectrum correct so what if it burned so hot it is literally invisible wouldent that be considered a dark matter then it's a dark matter sun

What will the scientific experiment look like that finds Dark Matter? Before then, what scientific/technological advancements will need to be made in order to find Dark Matter?

I am in college and trying to develop a theorem, If there is any information there is any papers or evidence to dark matter being particles could you please tell me as it will do me a great favor. Thank you for reading

I am an A2 physics student and I have chosen to do an Extended Project Qualification (EPQ) on 'What Is Dark Matter and To What Extent Is It Worth Researching?' I need to have a primary source of research for this and a forum thread seemed as good as any due to the opnion based nature of the...

That pesky 3.5 keV line just won't go away. The authors note that it's compatible with dark matter composed of 7.02 keV sterile neutrinos. If such is the case, the Majorana mass scale of the seesaw mechanism needn't coincide with the GUT scale (if such a scale even exists).

Observations have led to the conclusion that the Universe contains dark matter, a form of matter that has mass and therefore gravity, but apparently doesn't interact otherwise with 'normal' matter. It's existence is unexplained. Then there is the puzzle of antimatter, a form of baryonic normal...

In supersymmetric extensions of the standard model, the neutralinos and charginos (popular candidates for dark matter) are often included. However, it is known that these fermionic particles are linear combinations of supersymmetric bosinos (such as gauginos and higgsinos). Therefore, it seems...

I am hoping and I would most appreciate that one or more PF participants will be able to help me find out the following, either by posting answers or citing useful references. 1. What types of particles are candidates for being DM stuff? 2. For any of these candidates, are there estimates of...

This article of Dubois-Violette http://www.sciencedirect.com/science/article/pii/S0550321316300566 https://arxiv.org/abs/1604.01247 suggests that the diagonal in the exceptional jordan algebra H3(O) should be interpreted as chiral dark matter. Is it the same in other octonion-based models, or...

so, i love physics, and the more i look the more it seems our understanding of things are wrong. no planet #9, but now a mysterious planet-nine, dark energy, etc etc. so my question probably lies in theory, but getting close to applied physics. planet-nine, from what i have seen, the...

I wonder if someone can tell me if I have interpreted the cited article correctly. https://arxiv.org/abs/1306.5534 The article seems to have calculated upper bounds on the density of DM for different parts of our solar system. We have found that ρdm is less than 1.1⋅10−20 g cm−3 at the orbital...

What is exactly the dark matter? There are lot's of things hitting at a particle nature of dark matter I mean observation of the bullet cluster, freeze out times in the earlier universe, the third peak in the CMB power spectrum. I think there is no known consistent explanation by modified...

According to this paper https://arxiv.org/pdf/1701.03128.pdf is this a fudge factor or can we have a mixture of energies for DM. Abstract. Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark...

there is a lot of discussion about dark matter. Can black holes be used to explain this missing mass of the universe??

All the ordinary matter we can find accounts for only about 4 percent of the universe. We know this by calculating how much mass would be needed to hold galaxies together and cause them to move about the way they do when they gather in large clusters. Another way to weigh the unseen matter is to...

Baryon acoustic oscillations acoustic peaks in cosmic microwave background anisotropies provides evidence for cold dark matter but is there any sort of prediction as to the specific properties of this dark matter? predictions as to the mass of this dark matter, total mass, and mass of the...

In my quote above from the thread https://www.physicsforums.com/threads/ultimate-fate-of-the-universe.898640/ I omitted consideration of dark matter because so very little is known about it. I am hoping someone here at the PF might be able to discuss the following questions. QUESTIONS Assume...

I know that a black hole it's a singularity, but its event horizon gets bigger the more mass/energy you throw in. I thought that like dark matter interacts gravitationally with regular matter , it would interact with black holes, eventually falling , increasing the mass of the black hole and...

Ok - I have qualified this question with the word stupid so please go gently with me. Imagine you are talking to a rather stupid child when answering please. My question is about dark matter. Every time I do a search for "proof of dark matter", I get the same answer, which is that using the...

Hey guys, I was wandering that, if dark matter and dark energy makes up 68 and 27 percentage of the the universe, then is it justifiable to study these in terms of models of the known parts of the universe which comprises of less than 5 percentage of the universe, also it is clearly evident...

is it possible the dark matter in bullet clusters & CMB accoustic peaks were the result of black holes, originally from baryonic matter, but galaxy rotation curves are MOND. So MOND + dark matter as black holes from baryon, not dark matter particles

Thanks to all of you for your kind attention to my questions. May I ask another? If what we're calling dark matter interacts with visible matter via gravity, wouldn't it be concentrated along these arms if density waves are a feature of gravitational force?

I keep reading articles that assert that spiral galaxies would fly apart if it were not for the presence of a dark matter halo. The observation that rotational speeds vary little with distance from the center is usually cited as the 'proof' of dark matter since this behavior would otherwise...

Do we need more proof of dark matter than this?: https://en.wikipedia.org/wiki/Weak_gravitational_lensing

Unexpected interaction between dark matter and ordinary matter in mini-spiral galaxies "We studied 36 galaxies, which was a sufficient number for statistical study. By doing this, we found a link between the structure of ordinary, or luminous matter like stars, dust and gas, with dark matter."...

Hello, my name is Pedraam and I am newly getting into Astrophysics and stuff. It is very interesting to me so far! My question has to do with dark matter. I'm curious as to why we look at Newton and Einstein as such gods that if they're theory is slightly off, even in the cosmic world, we have...