Black Holes May Gain Mass From the Expansion of the Universe Itself

The first rendered image of a black hole, illuminated by infalling matter. In this study, researchers have proposed a model where these objects can gain mass without the addition of matter: they can cosmologically couple to the growth of the universe itself. Credit: Jean-Pierre Luminet, “Image of a Spherical Black Hole with Thin Accretion Disk,” Astronomy and Astrophysics 75 (1979): 228–35.

Over the past 6 years, gravitational wave observatories have been detecting black hole mergers, verifying a major prediction of Albert Einstein’s theory of gravity. But there is a problem — many of these black holes are unexpectedly large. Now, a team of researchers from the University of Hawaiʻi at Mānoa, the University of Chicago, and the University of Michigan at Ann Arbor, have proposed a novel solution to this problem: black holes grow along with the expansion of the universe.

Since the first observation of merging black holes by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015, astronomers have been repeatedly surprised by their large masses. Though they emit no light, black hole mergers are observed through their emission of gravitational waves — ripples in the fabric of spacetime that were predicted by Einstein’s theory of general relativity. Physicists originally expected that black holes would have masses less than about 40 times that of the Sun, because merging black holes arise from massive stars, which can’t hold themselves together if they get too big.  

The LIGO and Virgo observatories, however, have found many black holes with masses greater than that of 50 suns, with some as massive as 100 suns. Numerous formation scenarios have been proposed to produce such large black holes, but no single scenario has been able to explain the diversity of black hole mergers observed so far, and there is no agreement on which combination of formation scenarios is physically viable. This new study, published in the Astrophysical Journal Letters, is the first to show that both large and small black hole masses can result from a single pathway, wherein the black holes gain mass from the expansion of the universe itself.

Comparison of black hole merger observations with predictions from the new model. The horizontal axis shows the total mass of both black holes in any individual merger, relative to the Sun’s mass. The vertical axis gives a measure of how far into the past the merger was observed, where a redshift (denoted z) of 1 corresponds to when the Universe was half of its current size and z = 0 is today. The LIGO—Virgo observations are displayed as black crosses, with smaller crosses representing measurements with smaller uncertainties. Predictions for black holes in a static (not expanding) universe are shown in the orange region, with the darker shading representing more predicted objects. These are contrasted to predictions for cosmologically coupled black holes in a growing universe, which are shown in the blue region. Credit: University of Hawai`i, University of Chicago, University of Michigan at Ann Arbor

Astronomers typically model black holes inside a universe that cannot expand. “It’s an assumption that simplifies Einstein’s equations because a universe that doesn’t grow has much less to keep track of, said Kevin Croker, a professor at the UH Mānoa Department of Physics and Astronomy. “There is a trade-off though: predictions may only be reasonable for a limited amount of time.

Because the individual events detectable by LIGO—Virgo only last a few seconds, when analyzing any single event, this simplification is sensible.  But these same mergers are potentially billions of years in the making.  During the time between the formation of a pair of black holes and their eventual merger, the universe grows profoundly. If the more subtle aspects of Einstein’s theory are carefully considered, then a startling possibility emerges: the masses of black holes could grow in lockstep with the universe, a phenomenon that Croker and his team call cosmological coupling.

The most well-known example of cosmologically-coupled material is light itself, which loses energy as the universe grows. “We thought to consider the opposite effect, said research co-author and UH Mānoa Physics and Astronomy Professor Duncan Farrah.  “What would LIGO—Virgo observe if black holes were cosmologically coupled and gained energy without needing to consume other stars or gas?

To investigate this hypothesis, the researchers simulated the birth, life, and death of millions of pairs of large stars. Any pairs where both stars died to form black holes were then linked to the size of the universe, starting at the time of their death. As the universe continued to grow, the masses of these black holes grew as they spiraled toward each other. The result was not only more massive black holes when they merged, but also many more mergers. When the researchers compared the LIGO—Virgo data to their predictions, they agreed reasonably well. “I have to say I didn’t know what to think at first, said research co-author and University of Michigan Professor Gregory Tarlé. “It was a such a simple idea, I was surprised it worked so well.

According to the researchers, this new model is important because it doesn’t require any changes to our current understanding of stellar formation, evolution, or death. The agreement between the new model and our current data comes from simply acknowledging that realistic black holes don’t exist in a static universe.  The researchers were careful to stress, however, that the mystery of LIGO—Virgo’s massive black holes is far from solved. 

“Many aspects of merging black holes are not known in detail, such as the dominant formation environments and the intricate physical processes that persist throughout their lives, said research co-author and NASA Hubble Fellow Dr. Michael Zevin. “While we used a simulated stellar population that reflects the data we currently have, there’s a lot of wiggle room. We can see that cosmological coupling is a useful idea, but we can’t yet measure the strength of this coupling.

Research co-author and UH Mānoa Physics and Astronomy Professor Kurtis Nishimura expressed his optimism for future tests of this novel idea, “As gravitational-wave observatories continue to improve sensitivities over the next decade, the increased quantity and quality of data will enable new analysis techniques. This will be measured soon enough.

Reference: “Cosmologically Coupled Compact Objects: A Single-parameter Model for LIGO–Virgo Mass and Redshift Distributions” by Kevin S. Croker, Michael Zevin, Duncan Farrah, Kurtis A. Nishimura and Gregory Tarlé, 3 November 2021, The Astrophysical Journal Letters.
DOI: 10.3847/2041-8213/ac2fad

AstronomyAstrophysicsBlack HoleLIGOPopularUniversity of Hawaii at Manoa
Comments ( 42 )
Add Comment
  • Aleksandr7364

    An incorrect theory of non-existent gravitational waves led to an incorrect theory of growing non-existent black holes. It is good that you are not asked about the result – or else you would go bankrupt.

    • dw5674

      sorry, but “electric universe” is nothing but a bunch of disproven garbage . gravity waves are observed , and black holes most decidedly exist

      • Aleksandr7364

        So far, no one has refuted my theory. Reactive thrust waves press ships against each other – so atoms, quarks and strings are also attracted by reactive thrust of electromagnetic waves.
        https://www.youtube.com/watch?v=tFUM3vAlaGc

        • TheHeck

          So your “theory” is a youtube video? Doesn’t that explain why no one bothers to “refute” your “theory”?

          For your information, if it isn’t falsifiable, it isn’t a theory. You didn’t make any predictions that could be used to falsify your “theory.”

          Before you ask – yes, I watched your video, и Я говорю по-русски, и мне не нужны услуги переводчика.

          • Aleksandr7364

            Video in You Tube is a modern way of publishing. You have to keep up with the times. It is better than drawings on a rock, a clay tablet or a paper magazine. )) After my video, the universe becomes clear in the palm of your hand.

        • Torbjörn Larsson

          No, videos are not valid peer reviewed publications.

          And pseudoscience videos – as “electric universe” is well known to be – is an example why scientists demand peer reviwe publications.

          FWIW, the existence of the gravitational wave merger observations illustrated in the very article you should co0mment on – instead of pushing nonsense – reject your claim that such observations do not exist. *Those* observations are published in peer review journals, not in youtube social media.

          • Aleksandr7364

            Those waves can be anything – vibrating, explosive, detonation, but not gravitational. Because gravity is the reactive thrust of ordinary electromagnetic waves. And they are here underfoot, not millions of light years away.

    • pjcamp

      Gravity is not electromagnetic. Electromagnetism is spin 1. Gravity is spin 2. There are two different charges in electromagnetism. There is only one charge in gravity. The electromagnetic field is based on a U(1) symmetry. Gravity is a diffeomorphism.

      Having said that, I’ve interacted with plenty enough crackpots in my time to know that nothing will change your mind. You’re obviously right and nature has to change to conform.

      BTW, Youtube videos are a modern way of avoiding the scrutiny of peer review, where you will have to answer some tough questions about your arguments, questions that you don’t want to answer. But anything you put on Youtube is just BS.

  • mullach abu

    so give us an example eg
    the birth life and death of millions of pairs of large stars obsfgkm
    eg o star 1 radius x = ????? 0.25au
    o star 1 diameter y = ???? 0.5au
    and
    o star 2 radius x = ???? 0.25au
    o star 2 diameter y = ???? 0.5 au
    any pairs where both stars died to form black holes were then linked to the size of the universe starting at the time of their death
    eg o star 1 radius x at time of death = ???.5au?? size of black hole 1
    o star 1 diameter y at time of death = ???1au???? size of black hole 1
    and o star 2 radius at time of death = ???.5au?? size of black hole 2
    o star 2 diameter at time of death = ??1au????? size of black hole 2
    as the universe continued to grow the black holes grow up bigger
    black hole 1 diameter size 1.1au
    black hole 2 diameter size 1.1au
    as the universe continued to expand the masses of these black holes grew as they spiralled toward each other
    black holes Plus expansion of universe = cosmic coupling = black holes with what solar mass
    black hole 1 diamneter size 1.5au cosmic expansion constant
    black hole 2 diameter size 1.5au cosmic expansion constant
    as the universe continued to expand the masses of these black holes grew as they spiralled toward each other they merged
    black hole 1 and 2 diameter size 2.8 au includes cosmic coupling
    as you give no dimesions are these dimensions correct or in error by a factor of .5 .8 .9999999999999
    but you do give solar masses 40 50 100 trade u these for au and i might believe you
    but
    no stars expand
    no nebulae clouds expand
    just space and black holes cosmic coupled

    • TheHeck

      Lay off the schnapps, dude.

    • Torbjörn Larsson

      Read the article for examples.

  • BibhutibhusanPatel

    The theory of general relativity is còrrect wìth a time dependent proportionalty function of rotation.This is inherent to every galaxy with a different valùe is hard to measure and expressed as acceleration in the expansion rate.Acceleration bounded between limits and universe is homogeneous.So error occured in this method is within lìmits.

  • BibhutibhusanPatel

    The theory of general relativity is còrrect wìth a time dependent proportionalty function of rotation.This is inherent to every galaxy with a different valùe is hard to measure and expressed as acceleration in the expansion rate.Acceleration bounded between limits and universe is homogeneous.So error occured in this method is within lìmits.Universe is homogeneous,so coñstiuent matters and formula applied are samè for all galaxies.

  • Andres Albarran

    Well as the gateway behind the black “the white” continues to gain strength in the form of size growth, accommodation that occurs is the accumulation of more gravitation to stop it from endlessly pouring out into our existence as it is not contained nor stable in a sense the gravity acts in the same way scabs stop blood leakage. when it comes to a blackhole the rip in space is never ending so the scab continuesly grows endlessly never healing, one could say gravitation acts as a quarantine zone for an unknown core. since energy can not be destroyed only transformed it’s safe to say the atom is brand-new to our plain of existence and is considered by the conscious universe a possible “virus” that can’t be allow to spread.

    • Andres Albarran

      …it’s also possible that gravitation could be considered an incubation chamber which is feeding the core not quarantining it, the center could very well be an atom that would be capable of producing a big bang. something that is not necessary consider a “virus” by the universe yet presumably unstable so the spherical gravity that surrounds it acts as the nucleus as well as the “mother”in a sense that it absorbs energy which can very well be consider “food”. it hypothetically could be a form of neutron in dwarf state the energy of a neutron star compressed to the size of a baseball or perhaps even smaller its possible that without the gravitation the stellar body would be incapable of stabilization which would cause it to detonate before it’s time.

      • Andres Albarran

        With the use of Stephen Hawking’s research you can prove that it is both a quarantine zone as well as an incubation chamber. given the “virus” which occured due to the supernovae detonation was in my opinion detected by the conscious universe to perhaps be a brand-new element entering our existence, it could very well be an atom at the core something with two routes continues growth through absorption of objects which are perhaps used to further expand the size of the core which subsequently grows the gravitational nucleus in said method it is incubation. in the case that it isnt feed it dies through the gradual release of radiation so it dieing could be considered distribution of the brand-new element. perhaps the energy emitted needed to be encrypted into a formate which is understandable by our plain of existence which presumably the gravitation is capable of conducting in a method of remanufacturing. I’d assume pure state is to powerful to be kept as pure state or else quarantined incubation wouldn’t have been needed to begin with and supernovae would’ve been the end of it.

        • Andres Albarran

          Atom collisions at CERN as-well as the creation of a quasicrystal through fusion detonation further proves that the core of a black hole is possibly an element which is brand-new to our plain of existence. since even a star is an atom in it’s gigantic state and thermonuclear is a simulated micro form of supernovae “one” i myself personally would assume that during a full scale detonation a star which is again just an atom in a sense can produce something so brand-new it would subsequently be so unknown it’d need to be contained in a method that stops release at all costs for an x amount of time. Gravitational nucleus being the perfect method of containment a form of incubation which is capable of feeding it’s very much possible that a civilization does control the release and production of said gemstones.

          • TheHeck

            Dude, read up on the stars, thermonuclear fusion, and black holes before embarrassing yourself like this. I feel sorry for people like you. Really, I do. You have good intentions, but you think that reading a few snippets here and there, or watching some LoonyTube video makes you and expert, leading you to believe that your nonsense has any bearing on reality. Try to learn first, dude.

          • Torbjörn Larsson

            I have to agree with The Heck, if some responses to the article spouts random numbers without text others like you try to spout random texts without numbers.

            Neither makes sense.

  • Bob

    “The most well-known example of cosmologically-coupled material is light itself, which loses energy as the universe grows.”

    If the red-shift of light (loss of energy) is proof of the expansion of the universe, and the universe’s expansion is proof of the red-shift, are we not indulging in a circular argument? The loss-of-energy story reminds me of the “tired light theory” which seems not to be fashionable as it seems not to require an expanding universe.

    Over to you, cosmologists.Interesting idea that black holes suck the expansion of the universe and thus gain mass.

    • Torbjörn Larsson

      No, it is not philosophical (“circular”), see the illustration with observations against hypothesis predictions.

      General relativity has an energy description problem, so energy can only be defined locally (as for redshifting light or blueshifting GEODEs) or against our asymptotically flat space.

      Tired light was something else entirely, equivalent to dust mechanisms, and was immediately rejected by observations in the 30s (suggested diffuse light sources, but distant stars look point-like).

  • BibhutibhusanPatel

    Nothing is going to gain in an instant,as to cite mass of black hole.Every process is continuous.Difference is coming from the method of measurement.Can añy scientist ever dare to challange rotation is not sole effect of expansion to velocity of galaxy as determined by Hubble’s Law.So this not the first example to cite or to explain the phenomena to claim.

  • BibhutibhusanPatel

    Ñòt is simple expansion but accelerated expansion of galaxy increases the mass of black hols and super massive black hole at the center is suggested for clarification.This fact has already been discussed in the context of dark( unknown) energy/matter is wellknown.

  • BibhutibhusanPatel

    Ñòt is simple expansion but accelerated expansion of galaxy increases the mass of black hols and super massive black hole at the center is suggested for clarification.This fact has already been discussed in the context of dark( unknown) energy/matter is wellknown.
    The Scientists must be ŕecognised fòr their precìse and accurate measurement,able to calculate gain of mass by blackhole is òf great value.Thanks to the authors.

  • BibhutibhusanPatel

    Ñòt is simple expansion but accelerated expansion of galaxy increases the mass of black hols and super massive black hole at the center is suggested for clarification.This fact has already been discussed in the context of dark( unknown) energy/matter is wellknown.
    The Scientists must be ŕecognised fòr their precìse and accurate measurement,able to calculate gain of mass by blackhole is òf great value.Thanks to the authors.
    The time of observation limited to few seconďs is just important,that ìs the turning point where velocity of galaxy with rotatiòn to other galaxiès ìs observed is called acceleration in the expansion.

  • BibhutibhusanPatel

    Ñòt is simple expansion but accelerated expansion of galaxy increases the mass of black hols and super massive black hole at the center is suggested for clarification.This fact has already been discussed in the context of dark( unknown) energy/matter is wellknown.
    The Scientists must be ŕecognised fòr their precìse and accurate measurement,able to calculate gain of mass by blackhole is òf great value.Thanks to the authors.
    The time of observation limited to few seconďs is just important,that ìs the turning point where velocity of galaxy with rotatiòn to other galaxiès ìs observed is called acceleration in the expansion.

    However,this rate of expansion is not equal for all galaxiès.As all galaxies are not equal.
    But the galaxies are homogeneous,so that laws of physics are applicable same to all galaxies and their physical constituents are same or equal.

  • Cynthia Binder

    Gm Mon glad got ligo-vigro.all made sense, not the comments-funny.the article what is learned is data needs time an pieced together the simple result of common sense. Einstein said that,besides the simple is true. Glad to observe gravity wave,lord knows I felt something. So did earth. 11th dimension possible. Just a hobby.🤓🖖🖖🕳🕳besides general public is outsiders 😄 🤣 😂 hahaha really good work makes sense. Particles out👽👾👽🤓

  • .....

    Hello sir
    I want to say about time travel in past I have a one idea about it so if you interested so please email on parthradadiya850@gmail.com

  • .....

    Hello sir
    I want to say about time travel in past I have a one idea about it so if you interested so please email on parthradadiya850@gmail.com it’s about to travel in past

  • Kevin

    If this is true (and it does sound interesting), a rate of mass increase would be good to know. In addition, does this then mean that black holes cannot ever disappear as they will continue to add mass as the universe expands forever?

    • Torbjörn Larsson

      It does sound interesting, but the underlying hypothesis paper is problematic and the suggested objects and/or the effect they make as well (as that very paper notes!) – see my own response to the article.

      Their equation 1 gives the rate of mass increase. The reference hypothesis paper points out that it is insignificant for ordinary matter objects (stars and clusters), while if you take pure GEODEs their mass increase would scale with the cosmological expansion – but with k=3 in the equation, not their illustration example k = 0.5. They do exclude k >= 1 based on current data. So the basic example of GEODEs is out, and moving from a natural k=3 to small values close to 0 suggest the hypothesis is not very natural or robust.

      “For example, Equation (1) predicts that a C3O born at z_i = 25 with a coupling of k = 0.5 would double in mass by the time it is observed as a quasar at z = 6. A maximal coupling of k = 3 would increase the mass by 51×.”

  • Marcel

    L

  • Marcel

    Maybe someone can answer this for me. Is it possible that what makes up all of the dark matter which I understand is matter we can’t see. We already have objects with mass that can only be seen by gravitational warping of spacetime. such as black holes just moving around our galaxy. Could billions of billions of black holes just floating through our galaxy and even more in intergalactic space? The only way we can detect black holes if I remember correctly is by gravitational distortions. I know we can see the accretion disks/jets around black holes , but how many are out there really and is it enough to account for missing mass in the formation of the galaxy?

    • Torbjörn Larsson

      Early (“primordial”) and late (collapsed star) black holes have been excluded to make up the dominant part of dark matter based on such gravitational lensing observations.

      “Nevertheless, critics maintain that tight limits on their abundance have been set up from various astrophysical and cosmological observations, which would exclude that they contribute significantly to dark matter over most of the plausible mass range.[11]” [ https://en.wikipedia.org/wiki/Primordial_black_hole ]

  • Torbjörn Larsson

    It’s interesting, but to gain energy instead of lossing it through Hawking radiation the object would have to be a type of GEODE, with a de Sitter geometry inside. First author Croker is also first author on the paper that posits such backreaction through modifications of spacetime metric (but not the first derivative Einstein equations), and that paper claims pure GEODEs would have no spin while some other types self regulates general relativistic pressures amd so would have no backreaction.

    So we need more data (as the researchers suggest). 😀

    • xABBAAA

      …there, there, there…

  • B.H.Lightwell

    Do black holes have “holar” cycles. OoOoOo. No honestly is there enough LIGO data to detect patterns in the holar gravitational waves.

  • xABBAAA

    … more logical would be to test the hypothesis that it could come from some of the spinning and motion due to relativity effects and there is quantum theory with its virtual particles coming into space time…

  • king rocker

    Interesting concept, I like it. Where does the extra mass come from, if one is allowed the question?

    Otherwise, perfectly fine: as black hole radius is proportional to mass, therefore volume increases A LOT quicker than mass, the universe endgame then be a merger of all black holes and then perhaps a new birth?

  • John Bayer

    First time I’ve seen the claim (evidently incidental in this context) that light loses energy as the universe expands. Too much of a layman to immediately grasp this, I guess.

    • Corwin Zelazny

      The wavelength of radiated electromagnetic energy lengthens as the universe expands. And thus the energy in each particle of electromagnetic energy is spread over a wider area of space. The full energy is still there, it’s “smeared out” or “spread out”, one might say, and thus becomes much less available.

  • Corwin Zelazny

    Interesting theory. The one thought that keeps coming back to me is, what kind of mechanism? (I’m reminded of Fred Hoyle’s Steady State cosmological theory from the 60s-70s, where he argued that “negative energy” would operate to create new matter and space and to push the newly created space and matter apart.) I’m also wondering, how would this tie in with cosmic inflation? If a black hole gains mass from universal expansion, and the universe hit inflation running, well before the Dark Ages, then you would not need much more than minor singularities every few metres in the very early universe to seed it with some rapidly aggressively growing black holes.