I believe universe is cyclic too. I know my questions have no answer so far, but what could be the most reasonable answers for them. If baryonic matter is created at the BHs’ event horizon and at some type of stars, that means cosmological constant is not constant at all. But, if I believe in a cyclic universe, I need the cosmological constant to be constant to mantain a constant ratio between dark and baryonic matters which means that either the baryonic matter is created and destroyed at the same velocity, or dark matter has its own process to compensate and keep the ratio constant.

Regarding your post on the cosmological constant, see my post made just a few minutes ago at another question of yours. It gives a different definition to the cosmological constant, a definition that is not dependent upon the presence, absence, creation or disintegration of dark or baryonic matter.

https://www.researchgate.net/post/What_happens_to_the_antiparticle_unpaired_at_the_black_hole_event_horizon_that_remains_at_the_black_side_due_to_Hawkings_radiation_observation

Regarding a cyclic universe requiring an unchanging value of the constant, does that not implies the universe space is not curved, and is not expanding? Thus, the universe is constant, not cyclic?

Thanks Sydney. I am not philosopher yet!!! I am an engineer who has always been interested in the "big questions". I was educated in phisics, mathematics and chemestry. Philosophy is my pending subjet since I graduated in Engineering 27 years ago!!!

Thanks Peter for your answers.

Regarding your question, I'll try to do my best to explain what is my "certainly absurd idea" (CAI). It’s all pure speculation, although I will avoid conditional verbs form on writing.

I believe that there are two universes sharing one space-time. One of the Universes is made of regular matter and the other one is made of dark matter. A flat universe with two-in-one sides, a sheet made of “flat escalators” (as those at airports).

The edges of the escalators are:

1.- The black holes’ events horizon, which are “pores” between the two universe (the sinks of regular matter)

2.- The regular matter overflow edge at the Universe’s moving events horizon

At these two escalators edges both matters are exchanged. Globally the addition of regular and dark matters ratio keeps constant along the cycles, but the ration varies within each cycle. The more regular matter is converted into dark matter at black holes, the more dark energy pulls away light and regular matter to the Universe’s moving events edge turning dark matter into regular one and at the same time diluting it.

“Dark energy” (I dislike this term) pulls its space-time escalator to future, away from dark holes, away from stars nucleus, away from atom nucleus, in opposition to gravity and strong nuclear force. It pulls light to the moving Universe events horizon filling with regular matter and light the dark edge. Dark energy also pulls one of the two quantic particle-antiparticle pair to make regular matter emerge at the black holes’ events horizon’s quantic vacuum. This quantic vacuum occurs when gravity and dark energy are in an even opposition at the black holes’ events horizon.

On the other hand, gravity pulls its space-time escalator to past into the black holes, into the stars, into the planets, into the atom nucleus in opposition to “dark energy” and weak nuclear force. It kills light and makes matter dark, unaffected by light electromagnetic waves. Dark matter is the extreme consequence of gravity and strong nuclear force while regular matter is the consequence of “black energy” and weak nuclear force. Electromagnetism behaves like regular matter. The Doppler`s effect has something to be with that: frequency (inverse of wave length) increases due to gravity escalator movement and decreases due to dark energy escalator movement.

Regular matter and light are victims of “gravity” (the movement of space to past), and dark matter is victim of dark energy, the movement of space to future. This makes both at black holes’ events horizon and Universe’s events horizon time to be 0: past and future converge in other words, past and future are even. That means that, the more Universe approaches future the closer it is to its past and the other way around. Time doesn’t exist at all: it is just the movement of flat space which makes a time effect. We are regular matter so we move to future, but black matter moves the other way around. This makes also the Universe to be a three dimensions space, the coexistence of two opposite time arrows, although Universe is flat: Universe in a hologram.

Big bang was a quantic regular matter explosion of a black hole made of black holes. It happened when very large and critic dark vs. regular matters ratio was reached in a pre-existing Universe. This is the reason why Universe radio is much longer than 13.800 x 106 light years. And also is the reason why in fact Universe’s events horizons is limited in an infinite space-time. Once the regular matter is too low compare to dark matter, dark energy cannot bring enough regular matter to the dark edge but there is enough quantic vacuum at the huge black holes to explode and revert the dark vs regular matter ratio.

Every tiny weakness of this speculative idea is wellcome.

Arancha - In your theory you have used technical terms that have definite definitions in Cosmology, and while you are expressing "your" concepts using these well defined jargon terms, I feel many readers of a medium to high degree of expertise in the field of Cosmology will not be able to follow your thinking, due to the inherent limitations in the experts' ability, or inability, to read "your" definition into terms they have for years read to mean something other than your definition. You have borrowed liberally, perhaps to your theory's detriment. I state this for any expert reader who gets this far.

Regarding your theory, regardless of the jargon definitions, it is closer to a multi-verse, and perhaps even to string M-Theory with it's multiple branes, than to GR/QFT unified theories. Point is, no one can prove you wrong, they can just argue, and most of that will be based upon semantics of your use of existing jargon, and defining it differently than how mainstream does.

As far as my providing corrections or suggestions for refinement, I am too locked into existing theories, mostly mainstream, though I do read widely. And when I do read, I expect some mathematics to go with it, in order to be evaluated for predictive ability, which is what science today mostly requires for any adoption into mainstream thought and acceptance. So, my ideas would tend to morph you towards mainstream theories.

Instead, I can mention existing theories where your concepts might find a home, where possible refinements of both your theory and math theory might find common ground, a match, indicating some degree of finding the truth behind the reality of space and time, as we experience it, or otherwise.

I encourage you to continue to continue your quest. I am not sure that ResearchGate is the right place for theories that are not so close to mainstream GR/QFT or string/superstring/supergravity/MTheory concepts. I see you do wish to move towards a personal theory that reaches broader acceptance. In another thread you ask me for books that I have read in this area. I will post there shortly.

Peter Benjamin you are very kind. Someone less patient than you would have given up taking me seriously. Although a write absurd things none of them come from a crystal ball (I know it is difficult to believe :-)))))

Avoiding technical words and avoiding using them as jargon either, the questions are very basic in fact.

1.- Is there a beginning? I know we don't know, but I would like expertise like you funded opinions. Do you have any theory (or even wish) of your own which is less absurd than mine?

2.- Does existence comes from nothing?

3.- Does matter need a big bang to come to existence or could it appear spontaneously somewhere where reality is radically different, as at black holes for example? It is very suggestive the idea of a quantic particle forced not to join its dear antiparticle, turning avid to catch energy from the surroundings to turn into matter as a solution for its desperation.

4.- Does matter vanish? It is as well suggestive to imagine matter being disintegrated (or being found somewhere by its antiparticle) and resturning the borrowed energy to the Universe. What if our matter final destiny is to find its antimatter after trillions of recycling? They come to my mind many oriental non empirical understandings of the universe.

What is your opinion on Baum and Frampton's cyclic model?

Kind regards,

Dear Peter Benjamin again. Regarding my jargon abuse, you are right. I might try to defend myself arguing the right words are not yet invented for what I would like to explain but probably they exist but I don't know them.

Regarding Frampton, please read (if you find the time and wish to) the following: DOI 10.1088/1475-7516/2009/10/016. I am very much interested in Steinhardt, Turok and Frampton's ideas about Cyclic Universe. These three have the clue, I am sure.

Dear Arancha,

The current best measurements suggest the amount of matter, including dark matter, is constant, it is neither created nor destroyed in the current universe, and probably not since a very early era.

The observed "top down" structure formation requires that the DM is "cold", meaning the kinetic energy of its constituent 'particles' has always been less than their mass, hence the density decreases as (1+z)3.

For more information, which you will need if you wish to work on cosmology, you can find the final Planck Mission results here:

Preprint Planck 2018 results. VI. Cosmological parameters

George Dishman If I didn't misunderstand you, total matter remains constant, that it is what I believe too, but, what about the ratio DM vs. "observable matter"? Any fluctuation has been dettected in 13.800 x 106 years? What about the differences in density observed in the CMB? Could they be fluctuations occured in the pass in that ratio?

I will carefuly read what's in the link you shared with me.

Many thanks,

Arancha

Dark matter has not been found. The time elapses suggests it should have been found. So, best to consider it an illusion and look for other causes of spiral galaxy rotation curve.

Hi Aranacha,

The energy density of cold matter falls as (1+z)3, that for radiation falls as (1+z)4 and dark energy is constant. We can only measure the combined effect of the sum of those densities on the rate of expansion so we can't measure the ratio of dark to light other than by totalling the luminosity of galaxies. This is an appendix to a series of lectures, they show how the three equations of state work out but you could also go through the main lectures to see if they help.

http://nicadd.niu.edu/~bterzic/PHYS652/Appendix_06.pdf

Lecture index:

http://nicadd.niu.edu/~bterzic/PHYS652/index.htm

P.S. Lecture 18 may be of particular interest.

Dark matter has these "facts" known about it.

1) Dark matter was originally suspected due to the velocities of galaxies as calculated by Zwicky in his 1933 paper. The next clue was the orbital velocity of the outer stars in a few observed galaxies. Now, observations have data on hundreds of galaxies, or so. Not that many, given the billions that exist.

2) A second method for detecting and measuring the density of dark matter around galaxy has been found. Many galaxies have been recorded as bending light from galaxies behind it, and allowing the distribution of dark matter to be calculated. Many galaxies have this data published. Around 100, a very few, too few to reach conclusions.

3) A few galaxies, under 10, have been published as having no dark matter, that some consider disproves the existence of dark matter. The number is too few to draw conclusions.

4) No one has published definitive proof dark matter exists.

5) One can not use the math based on a concentric spherical distribution of matter density to calculate the force of gravity for a galaxy stars orbital velocity around the center of the galaxy. To calculate velocities, one but must integrate over the actual distribution density of matter.

6) A pair of scientists published an article detailing the forces of gravity using an approximate distribution of stars in a galaxy, and found the outer stars had the proper velocity, that is, matching the observed data.

The above facts are not about "reality" of spacetime or QM, but about human endeavors, what has been written, and therefore there is no dispute these facts are true.

PB: 1) Dark matter was originally suspected due to the orbital velocity of the outer stars in a few observed galaxies.

Wrong. Dark matter was first described by Zwicky when he applied the Virial Theorem to the dispersion of the velocities of galaxies in the Virgo Cluster.

PB: ... there is no dispute these facts are true.

Wrong again, I just disputed your first "fact" and the rest isn't much better.

George Dishman

Not quite. Zwicky coined the term "dark matter" . But the observation he made was explained by baryon matter in the x-ray band. The "dark matter" of today was as Peter said.

@George Thank you for bumping my recollection. I've corrected my post.

I'm very interested in where you read the proof of dark matter's existence. Did it include a response to the other two points that tend to disprove dark matter?

Hi Peter,

PB: I'm very interested in where you read the proof of dark matter's existence.

Although not the first historically, I see the primary evidence for dark matter being:

• the abundance of primordial deuterium
• the near zero curvature measured by the Planck Mission
• the rate of galaxy formation in the early universe (the statistical variation at the time of the CMB is too small to allow galaxies to have formed in the age of the universe)
• the existence of Baryon Acoustic Oscillations
• the angular frequency of the first peak in the CMB power spectrum
• the fact that galaxies formed "top down" instead of "bottom up"
• the fact that one or two galaxies have been found which have no dark matter signature meaning it cannot be a flaw in our theory of gravity
• and most recently the coincidence of the gamma ray and gravitational wave arrivals in GW170817

For the last of that list, see:

Article GW170817 Falsifies Dark Matter Emulators

Zwicky's work on the Virgo Cluster in your point (1) and point (2) favour DM.

Your point (3) also is actually evidence in favour of DM, and I think (6) is similar, since an error in modelling gravity would have to apply to all galaxies, no exceptions.

Your point (5) is partly correct but the DM is a spherically symmetric halo with the normal matter being a thin disc within it. The bulk of the mass is in the core so the thin disc mass is an order of magnitude smaller than the DM hence the maths is valid as an approximation. For serious work though, the effect is integrated as you say, see for example the NFW and Einasto profiles.

Overall, every point raised in your post and mine tend to support DM and none suggest it is wrong and it is this multiplicity of different observations that scientists accept is the evidence for the existence of DM. No one alternative could explain all these separate pieces.

Dear George Dishman . So thankful for your links. My questions make sense!

Arancha

Dear George Dishman ,

I am back again. In Appendix to Lecture 6 you have shared with me above, when speaking about "energy of matter" I must assume just "observable matter", right? Dark matter doesn't play any role in the equations, does it? It is good to know that it can be calculated the moment when both energies were made equal. May I understand that since that moment, dark energy increases while matter energy decreases?

Dear George Dishman .

I promise I'll give up making questions after the next one for a while. Please, tell me if my conclusions after reading the Lecture #18 are right: dark matter appears when cross-section of a particle decreases below a critical length. That would mean that dark matter could be generated due to Universe’s freeze out at “the end of time”. But could it be possible that the annihilation of matter into dark matter happens the other way around, due to compression at huge gravities as the ones inside dark holes?

Thanks in advanced for your patience

Dear Peter Benjamin

There are two ways of approaching everything. There is a way, like yours and many others’, that prefer not to imagine how things work until you "put your hands in the wound" (this is a literally translation of an Spanish phrase that regards to St. Thomas' incredulity), and there is another way, which is the one that seems more interesting to me, and that has nothing to be with credulity but with explaining “why” without any misterious God behind. So, if there are 100 galaxies over trillions where DM has been deducted (no matter how, I trust because the authors of those discoveries know much more than me) and there are 10 where it couldn't be, let us think DM exists 90,9% and let It explain us how things could work.

The two approaches are not wrong: the last one brings me much more pleasure than standing in the middle of Cosmos, adding equations to my backpack and waiting for evidences. “To Caesar which is Caesar’s” (another reference to the Bible) because I don’t pretend to discover the wheel!!! But I make my best to understand the latest knowledges and to give them a thought. I don’t need to re-study infinitesimal calculus or fluids mechanics for that (althouh I had a little recently). A certain background is enough because It let me understand integrations, limits, vectors, and many stuff, and it let me know if something is out of my comprehension too. QM is out (it is too late for me) for sure, but it is a very good warehouse of fabulous dreams. I don’t know a thing about QM equations, but I can get QM's point and dream. This is my only goal as engineer compared to pure philosophers.

Besides all the above, I am almost 100% sure you have your own idea on how things work, don’t you? This is truly my interest: sharing with someone like you, who understands almost every equation that is produced, what you conclude about the big amount of equations you certainly know.

Come in, the door is open ;-)

Hi Arancha,

AC: In Appendix to Lecture 6 you have shared with me above, when speaking about "energy of matter" I must assume just "observable matter", right? Dark matter doesn't play any role in the equations, does it?

No, the famous equation E=mc2 applies to all matter whether we can see it or not so dark matter contributes, and in fact is about 6 times more than the visible matter.

AC: It is good to know that it can be calculated the moment when both energies were made equal. May I understand that since that moment, dark energy increases while matter energy decreases?

Dark energy stays at a constant density as far as we can tell, that's why it's a horizontal line on the diagram, but matter and radiation continue to fall.

Neutrinos are interesting, they have a very small mass, possible around 0.1eV, so when they were moving at nearly the speed of light in the early universe, they would be part of the "radiation" factor but once their kinetic energy fell below that level, their speed would drop and they would be counted as "matter". Their line on the chart would be (1+z)4 at first but then curve to become (1+z)3 from roughly 106 years (if my own calculations are correct, that's not a number I've seen quoted anywhere).

AC: Please, tell me if my conclusions after reading the Lecture #18 are right: dark matter appears when cross-section of a particle decreases below a critical length.

I tend to think of the freeze-out more in terms of temperature, there's more on that in Lecture 17.

AC: That would mean that dark matter could be generated due to Universe’s freeze out at “the end of time”.

No, the freeze-out happened when the mean thermal energy drops below the particle's mass or a little later. We don't know the mass of WIMPs (if they are the right answer) but they would be heavier than electrons. Those have a mass of 511 keV compared to ~2eV for visible light, so you can see the temperature for electron/positron pair production has to be where thermal radiation peaks in the gamma range, and WIMPs would need a much higher temperature. The "freeze-out" would have happened in the first few microseconds of the universe, after that it was too cold. That's why the amount of dark matter has been constant ever since.

George Dishman

Many thanks for your answers and your dedication... You make things very easy to understand.

Freeze-out was the freeze at the begining, not at the end as I understood!!! ;-) I was thinking on the Big Freeze. By the way, do you think Universe will reach that point or will bounce before?

So, as a resume of my previous questions (just to confirm that I have a clear picture in my mind), your reaserching brings you to the following approaches:

1.- At the freeze out temperature all the dark matter was created and it keeps constant from that time as Universe temperature is too low since then (what about the temperature inside the BBHH? Don't they behave like "black bodies"?)

2. If DM's keeps constant, what happens to its density as space expands? (I could spend my entire life asking!!!!)

3.- "Bright" matter (BM) was formed at the freeze out temperature or around. Its energy was greater than dark energy, whose density remains constant along time. At a certain moment, matter energy, that was decreasing, reached dark energy amount. Not only its energy but also matter itself (and radiation) are going down.

4.- Dark energy density, as said above, remains constant. But, if space is expanding couldn't we think DE encreases in the same proportion maintaining its density constant? If this is the case, what could be the source?

5.- We could be forced to believed that there is not matter transference between DM and BM, nor energy between DE and BE. then, where does all the bright matter and radiation that Universe is losing go?

Looking forward your answers... Arancha

Hi Arancha,

AC: Many thanks for your answers and your dedication... You make things very easy to understand.

Thanks, glad I could be of help. There's a great deal to learn in this field the best I can do is point you in the right direction.

AC: I was thinking on the Big Freeze. By the way, do you think Universe will reach that point or will bounce before?

Unless something changes dramatically, there can't be a bounce, the expansion is already accelerating. For a cyclic model I would expect a "big freeze" in which everything decays and densities drop to nearly zero, less than one atom per Hubble volume, but then perhaps a random quantum event will create a new "big bang" within that environment. Nobody knows, that's all speculation.

AC: 1.- At the freeze out temperature all the dark matter was created and it keeps constant from that time as Universe temperature is too low since then ..

Yes.

AC: (what about the temperature inside the BBHH? Don't they behave like "black bodies"?)

Probably, we think they give out thermal energy as Hawking radiation but the temperature has to be less than the CMB before they can lose mass that way, until then the input is greater than the output, so the temperature will be much less than 1K and you need very high temperature to create particles. The radiation will be pure photons until the last second or so like this:

https://jila.colorado.edu/~ajsh/bh/hawk.html

Check out the teaching material on Hamilton's site too, he's highly respected in this field:

https://jila.colorado.edu/~ajsh/

AC: 2. If DM's keeps constant, what happens to its density as space expands? (I could spend my entire life asking!!!!)

If you put stuff in a box then double the length of each edge, the volume goes up by a factor of 23=8 so the mean density goes down by that too. That's why matter density falls as (1+z)3, (1+z) is the distance scaling factor.

AC: 3.- "Bright" matter (BM) was formed at the freeze out temperature or around.

Each species will "freeze" at a different temperature depending on its mass. Have a look at BBNS in general:

http://www.astro.ucla.edu/~wright/BBNS.html

If you haven't seen it yet, make sure you go through Ned Wright's tutorial, it may fill in some gaps for you:

http://www.astro.ucla.edu/~wright/cosmo_01.htm

AC: [DM's] energy was greater than dark energy, whose density remains constant along time. At a certain moment, matter energy, that was decreasing, reached dark energy amount. Not only its energy but also matter itself (and radiation) are going down.

The density of matter falls, the amount per co-moving volume is constant, the volume is expanding.

4.- Dark energy density, as said above, remains constant. But, if space is expanding couldn't we think DE encreases in the same proportion maintaining its density constant? If this is the case, what could be the source?

That's a tricky one to grasp, the energy density has a corresponding negative pressure, and pressure contributes to gravity as well as the more usual source we think of, mass. Because the pressure is negative, the gravity it creates is repulsive, hence it accelerates the expansion, but doing work against negative pressure gives you energy, so the end result conserves the total, no new energy is needed :-) It's sometimes called the "free-lunch" model. Again, Ned Wright has a good explanation:

http://www.astro.ucla.edu/~wright/cosmo_constant.html

5.- We could be forced to believed that there is not matter transference between DM and BM, nor energy between DE and BE. then, where does all the bright matter and radiation that Universe is losing go?

Matter doesn't "go", it just gets more spread out but it's still there. Cosmological radiation gets redshifted so loses (1+z) but the number of photons is conserved and they are again just spread out so that gives the other (1+z)3 to give (1+z)4 in total. The "lost" energy can be thought of in the same way that a photon shone up into the sky loses energy by gravitational redshift, but that depends on frames and things, it's similar to Doppler which doesn't lose energy in total even though a moving observer sees a reduced frequency. It's a messy piece of book-keeping.

Hi George,

Nice to meet you here on RG. I appreciate your long list of dark matter evidence, as I had only come across half of them. I have some reading ahead of me.

This post is a clarification of my perception of your opinion of the brief list of "facts."

Your apparent opinion of my post, and I may be wrong of your opinion, was the post was an attempt to list facts that disprove the existence of dark matter. My post was not that. The post should not be taken as attempting to disprove the existence of dark matter.

My post was 'true' facts on human publishing about dark matter.

It was intended for lay readers, to put perspective on a few popular press approaches to dark matter's existence. The press likes easy concepts that are "well known" to the lay person, like galaxies are made of stars, that orbit the center, similar to the solar system. I was writing for the lay reader, given the degree of expertise of the original poster, Arancha, not for experts like you.

Your terrific list includes concepts that I feel lay people have little chance of understanding the technical terms, even with a few days of solid reading up on them. A very suitable list for RG.

My belief on the existence of dark matter is suspended, pending directly measuring any dark matter particles. Upon measuring dark matter particles, at that time my belief will no longer be suspended, and I will expect mainstream journals to provide peer reviewed "proofs" of dark matter existence. These articles should be full of math squeezing dark particles into the Standard Model, a feat to be witnessed.

The items that you listed are very good justifications for allocating funds to continue searching for dark matter evidence, and attempting to directly measure them, a feat that no one currently knows how to do, but a dozen or more scientists have proposals seeking funding. A good thing.

Dear Arancha Ceada,

Science is done your way, with the imagination first, and the math comes afterwards.

Original thought is not something everyone can do. Thinking original concepts is something only a few people out of thousands will do.

These thinkers are treasures to mankind.

They invented the thrown rock to feed the tribe, fire, the spear, wheel, sword, bow and arrow, electricity, computer chip, rocket to outer space, all things to ensure the survival of the species. I only listed the top original thoughts, to show great inventiveness is a long process, and rarely happens.

It is why I responded to your project's posts. To encourage. But at the same time, I do not want to encourage you to only adopt those things that have already been invented, by other scientists, as they have published and you read.

I want you to try for original thought.

I think the survival of mankind demands we have more original thinkers.

Math is used as a language of convenience, of conciseness, to convince yourself. And to convince one's peers of the correctness of your publish thoughts. That the soft sciences would have such a tool, would be great (they do in statistics).

A side note, the authoring of an article, the act of publication, is a step that is well separated from the approach of doing original thought science. Such publication brings the author rewards for his becoming a treasured contributed to the species survival.

George Dishman

I think that with all the explanations and links you have shared with me, I have a good portion of the material I will need for my End of Master Project on Cyclic Universe Model.

It seems that probably only a quantic event could make Universe to come back if an 11 D Universe doesn't exist as predicted by strings theories.

There will be a time in which Humans will be able to truly understand what is behind QM, what makes vacuum so interesting. I know very few about it, but from the very little I understand I may say QM is an absolute challenge for mind. Just the surface of QM is challenging enough for me.

I will keep all your posts as jewells in a treasure box.

Many, many thanks.

Arancha

I'm glad I could be of help, it's a fascinating and rapidly evolving topic so good luck with your project.

Best regards,

George

Preprint Dark Matter Might Reside in Extra Physical Dimensions

Ahmad Yousef

Many, many thanks for your link. Indeed it helps to my own conclusions.

Arancha