https://aasnova.org/2023/02/15/black-holes-as-the-source-of-dark-energy/ * AAS * AAS Journals * BAAS * AAS-IOP eBooks * AAS Nova * AASTeX * Astronomy Image Explorer * Unified Astronomy Thesaurus * WorldWide Telescope AAS Nova [ ] [Search] Navigate * HOME * Highlights * Journals Digest * Twitter * Facebook * RSS Black Holes as the Source of Dark Energy By Kerry Hensley on 15 February 2023 Features Share: Twitter Facebook LinkedIn Google+ Reddit Email Visualization of the accretion disk around a black hole Visualization of the accretion disk around a black hole. [NASA's Goddard Space Flight Center/Jeremy Schnittman] What do black holes have to do with dark energy, the subtle pressure that accelerates the expansion of our universe? New research suggests that the two may be inextricably linked, potentially solving the long-standing mystery of the nature of dark energy. Multiple Black Hole Models annotated illustration of a black hole Illustration of a traditional black hole model with important components of the model labeled. Click to enlarge. [ESO; CC BY 4.0] When a massive star ends its life, it collapses to form a black hole, creating a well in spacetime so deep that even light cannot escape. Although our understanding of black holes has grown over time, there's still much we don't know about them, and we rely on mathematical models to learn more and make predictions that we can test. The most common model predicts a spinning black hole containing a singularity -- a point of hypothetically infinitely curved spacetime where our equations describing gravity break down -- hidden by the black hole's event horizon. However, this common black hole model is in tension with the overall expansion of the universe, leading some scientists to propose alternative models. In one such model, black holes do not contain a singularity, but are instead filled with vacuum energy. These vacuum-energy black holes are intriguing because their growth is coupled to the expansion of the universe: as the universe expands, these black holes gain mass. Do Black Holes Gain Mass as the Universe Expands? In a research article published today, Duncan Farrah (University of Hawai`i) and collaborators tested this black hole model by studying the growth of supermassive black holes over billions of years. The team studied elliptical galaxies since these galaxies' central supermassive black holes are unlikely to grow much by other means, such as by consuming nearby stars and gas. plots of probability versus cosmological coupling strength The probability of different coupling strengths as derived from several different data sets. The results are incompatible with traditional black holes (BHs), which are not coupled to the expansion of the universe. [Farrah et al. 2023] By measuring how the masses of black holes at the centers of elliptical galaxies billions of years ago compare to those present today, Farrah and coauthors determined the strength of the coupling between black hole mass and the expansion of the universe. Traditional singularity-containing black holes would have a coupling strength of 0, while vacuum-energy black holes would have a coupling strength of 3. Ultimately, the team found the coupling strength to be around 3.11, and they ruled out the possibility of zero coupling at 99.98% confidence. This finding supports the vacuum-energy black hole model and suggests that black holes do gain mass as the universe expands. Dark Energy, Illuminated plot of star formation rate density as a function of cosmic time Star formation rate density (SFRD) as a function of redshift. The green shaded area shows the possible star formation rates that will yield the density of black holes necessary to produce the observed dark energy density. The solid lines show the model results for different initial mass distributions of newborn stars. Click to enlarge. [Farrah et al. 2023] What does it mean for black hole growth to be linked to the expansion of the universe? Certain physical quantities must be conserved as black holes gain mass, and as a result, the growth of black holes produces pressure that drives the acceleration of the universe's expansion. In other words, black holes that grow as the universe expands are a source of dark energy, a long sought-after component of our models of the cosmos. Farrah and collaborators performed additional modeling showing that the expected population of vacuum-energy black holes can account for the density of dark energy previously measured by the Planck satellite -- so not only do vacuum-energy black holes generate dark energy, they generate the same amount of dark energy we've measured! Hopefully, the next few months to years will bring more research on this topic, expanding our understanding of the fundamental physics of our universe. Citation "Observational Evidence for Cosmological Coupling of Black Holes and Its Implications for an Astrophysical Source of Dark Energy," Duncan Farrah et al 2023 ApJL 944 L31. doi:10.3847/2041-8213/acb704 black holes cosmology dark energy * RELATED HIGHLIGHTS + a spiral galaxy with two long, distinct spiral arms and a central bar 10 February 2023 Features 0 First Look at Extragalactic Cepheid Variable Stars with JWST + artist's impression of a tidal disruption event 25 January 2023 Features 0 A Survey of Shredded Stars + computer visualization of a binary supermassive black hole system 10 October 2022 Features 0 Insights from Misaligned Black Hole Pairs + Hubble Space Telescope image of the dwarf spiral galaxy NGC 5949 9 August 2022 Astrobites 0 Not All Black Holes That Wander Are Lost -- and Now, Some May Have Been Found + An artist's impression of a stellar-mass black hole 29 July 2022 Features 0 Micro Tidal Disruption Events in Massive Black Hole Disks * AAS Journals Fully Open Access in 2022 AAS Journals Fully Open Access in 2022 The entire AAS journals portfolio is freely accessible as of 1 January 2022. Find out more. New AAS-IOP Publishing Ebooks New AAS-IOP Publishing Ebooks The AAS has partnered with IOP Publishing to create an exciting new collection of astronomy and astrophysics ebooks to further the AAS mission: "to enhance and share humanity's scientific understanding of the universe." Research Notes of the AAS Research Notes of the AAS Need a place to publish works in progress, comments and clarifications, null results, or timely reports of observations in astronomy and astrophysics? RNAAS is open for submissions. * HIGHLIGHT HOT TOPICS exoplanets star formation solar system stellar evolution AAS meeting AAS publishing magnetic fields planet formation black holes interstellar medium atmospheres supermassive black holes active galactic nuclei mergers gravitational waves * MOST READ RECENT HIGHLIGHTS 1. Black Holes as the Source of Dark Energy 2. First Look at Extragalactic Cepheid Variable Stars with JWST 3. Creating a Perfect Solar Storm 4. JWST Reveals Star-Formation Details in a Dusty Galaxy 5. Four Perspectives on Neutron Stars, Pulsars, and Magnetars * Email alerts Please leave this field empty[ ] Sign up to receive email alerts when new Highlights articles are published. Please supply your email address. Email *[ ] Select list(s):[ ] Highlights Instant Alert[ ] Weekly Highlights Digest [Subscribe] The AAS will never rent or sell your email address to third parties. Check your inbox or spam folder now to confirm your subscription. [AAS-NOVA-l] The American Astronomical Society (AAS) is the major organization of professional astronomers in North America. The mission of the AAS is to enhance and share humanity's scientific understanding of the universe. AAS Nova highlights results published in the AAS's peer-reviewed journals. It provides a curation service to inform astronomy researchers and enthusiasts about breakthroughs and discoveries they might otherwise overlook. AAS JOURNALS * The Astronomical Journal * The Astrophysical Journal * Planetary Science Journal * The Astrophysical Journal Letters * The Astrophysical Journal Supplement Series SITE INFO * About & Contact * Copyright & Permissions * Privacy & Cookies * Terms (c) 2019 American Astronomical Society. All rights reserved.