Cosmology Forum

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Join in expert discussion on topics revolving around cosmology. Cosmology is the origin, evolution, structure and eventual fate of the universe.
Undergrad What temperature would 1 keV neutrinos have today?
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Undergrad "Energy is not conserved" vs. energy is conserved: Friedmann Equations
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Undergrad Questions about paper "How closed is cosmology"
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Undergrad Brian Cox and the end of the Universe?
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Undergrad Latest Findings from DESI Collaboration
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Undergrad I'm slightly confused about the power spectrum of matter
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High School Question About Dark Energy
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Undergrad Speed of light on cosmological scales
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Undergrad Cosmological Scalar Field Density Dilution
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Graduate Matter density crude estimates
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High School Percentage of known energy in the Universe
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High School Pressure on creation of the Universe
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High School Can the "creation" of space in the Universe affect the speed of light?
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Undergrad Global properties of the universe
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Undergrad Can there be structures made from neutrinos with angular momentum?
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Undergrad Do Cosmological Models Influence Quantum Field Theory?
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High School History of CMB, prediction of 1 in 100,000?
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High School Expansion of the Universe
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Undergrad Post Big Bang Gravity
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High School Big Crunch in an infinite, symmetrical, Newtonian universe?
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Undergrad Question about the big bang singularity
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Undergrad Questions about the accelerating Hubble expansion
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Undergrad Has JWST solved the crisis in cosmology?
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Undergrad Inflationary vs deflationary phase of Big Bang
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Undergrad Meaning of the distance between galactic objects in GR
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High School Matter-antimatter asymmetry - a simple explanation?
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Undergrad Expanding Universe without dark energy
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High School Dark energy might not be constant after all
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Undergrad Is there an equivalent "redshift" for cosmic rays due to expansion?
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Undergrad The Evolution of Galactic Scale Cosmic Voids
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Graduate What is the maximal comoving distance that a space probe can reach?
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Undergrad Vacuum up-tunneling with high-energy events?
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Undergrad Is Vacuum Decay from a False to True State Impossible or Just Unlikely?
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Graduate A question from a paper on perturbation theory
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Graduate Friedmann-Lemaitre-Robertson-Walker model
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Undergrad Fourier transform of the density fluctuation
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Undergrad What is the Freeze-Out Temperature of WIMP Particles?
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High School Can the force of gravity overcome the Planck force?
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High School Do we 100% know what the geometry of the Universe is?
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Undergrad Do the Sachs-Wolfe and Rees-Sciama Effects Influence Matter?
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Undergrad Relationship Between Expansion and Curvature in the Universe
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Undergrad How Does Curvature Density Parameter Affect Universe Flatness?
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High School Could Dark Energy be an (unknown) dark force acting at great distances?
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High School Question about Hawking Radiation and Iron Stars
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Undergrad Boltzmann equation for annihilation
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Undergrad Voids, dark energy and tidal forces...?
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High School Where does the original singularity get its energy from?
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Graduate Could Re-Analyzing Redshifts Reveal New Physics?
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High School Cosmic Graviton Background and Primordial Gravitational Waves
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High School Observable universe and overlapping spheres
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High School Dark matter and extreme gravitational regimes
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Undergrad On Quanta article on the recent tensions of cosmology
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Undergrad Calculating the End of the Universe Using Standard Deviation Statistics
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Undergrad Mass in an expanding or static spherical distribution of matter
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High School Is perpetual motion a forbidden topic in the scientific community?
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Undergrad Questions about the Location of the Big Bang and the Age of the Universe
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High School Comoving distance constant with increasing redshift?
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Undergrad How does flux density scale with redshift?
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Graduate Numerical evolution of Einstein-Boltzmann equations in cosmology
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Graduate Gravitational Instability and accelerated explanation of Universe?
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Undergrad Photons being blueshifted when crossing evolving voids?
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Undergrad Falling into a massive black hole is not necessarily noticeable
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Graduate What Is the Scale Length in SPARC Data Analysis?
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Undergrad Big bang at the edges of the Universe?
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High School What is the Borde-Guth-Vilenkin theorem?
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Undergrad Does dark-energy require a source of energy?
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Undergrad Rotation curves and apparent mass of a galaxy
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Undergrad Is there any mechanism possible for the Big Brake?
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Undergrad Did James Webb cast serious doubt on the Big Bang?
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Undergrad Dark energy and the kinematic Sunyaev-Zeldovich effect?
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Graduate What is the origin of the Dipole Repeller and similar structures?
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Graduate Planck evidence for a closed universe and a crisis for cosmology 2019
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Undergrad Avoiding structure collapse due to dark energy?
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Undergrad Why didn't the Big Bang form a Black Hole?
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Undergrad More extended equilibrium configurations due to dark energy?
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Undergrad Question on multiple rebrightening gamma ray bursts and gravity waves
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Graduate Convention of units for densities in cosmology
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Undergrad Dark Energy contribution to plasma temperature in galaxy clusters?
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Undergrad Is Tipler's Theory of Immortality Worth Considering Without Religious Bias?
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Undergrad Big bang occuring everywhere vs everything "compressed"
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Undergrad Using GR to predict the shape of the entire universe?
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Undergrad Understanding Space-Time Expansion: Debunking the Myth of Non-Physical Space
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High School What value of z (redshift) equals apparent superluminal recession?
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Undergrad Limitations of Observing Distant Space Objects
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Graduate Save Time with CLASS Code: Neat Trick for Background Quantity Evolution
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Undergrad Tidal effects of galaxies orbiting one another with dark energy?
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Undergrad Why Is a Flat Universe Infinite?
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Undergrad What are P03 procedures or guidelines?
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High School Roger Penrose model of the rebirthing universe
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High School How did expansion take 380,000 years to let light travel freely?
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Undergrad Cosmological expansion of space - question
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Undergrad Same state as in the Big Bang in a collapsing universe?
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Undergrad Dark energy contributing to, or modifying, mass estimates?
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High School The distance to the nearest identical Hubble volume in light years?
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Graduate Poisson noise on ##a_{\ell m}## complex number: real or complex?
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Undergrad What was expansion speed at the time of the CMB?
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Why is spacetime shown on a 2 dimensional plane?
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Undergrad The boundary conditions at infinity
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Undergrad Unobservable Universe and the CMBR
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Undergrad Would there be any way to avoid gravitational wave emissions?
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