Cosmology Forum

Post thread
Join in expert discussion on topics revolving around cosmology. Cosmology is the origin, evolution, structure and eventual fate of the universe.
Graduate Explore Holographic Dark Energy: Edmund J. Copeland et al.
  • · Replies 1 ·
Replies
1
Views
3K
Undergrad Why is this Hubble plot linear for Omega=2 closed universe?
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad What will eventually happen to all EM waves / photons?
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad Are MOND Equations Consistent Across Sources?
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Dark Matter Real: Studies Confirm, Modifying Gravity Can't Work
  • · Replies 156 ·
6
Replies
156
Views
24K
Undergrad Was Dark Energy Dominant Over Matter in Early Universe?
  • · Replies 5 ·
Replies
5
Views
2K
High School The singularities of gravitational collapse and cosmology
  • · Replies 45 ·
2
Replies
45
Views
8K
Undergrad Does the newly measured expansion rate change the odds for Big Rip?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Expansion of the Universe question
  • · Replies 3 ·
Replies
3
Views
2K
High School If the universe were played in reverse, how would it differ?
  • · Replies 3 ·
Replies
3
Views
10K
Undergrad Universe younger and faster than thought
  • · Replies 15 ·
Replies
15
Views
3K
Undergrad Will the Big Rip basically be the Big Bang for the next universe?
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad Is the age of the Universe "boundless"?
  • · Replies 4 ·
Replies
4
Views
2K
Graduate Different FRW Cosmological Models
  • · Replies 7 ·
Replies
7
Views
2K
High School What A White Hole Will Look Like?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Provide me the paper by Peebles,P.J.E 1980 and 1993
  • · Replies 1 ·
Replies
1
Views
1K
High School What does 4 D spacetime look like?
  • · Replies 27 ·
Replies
27
Views
7K
Undergrad Helium Hydride data, Early universe chemistry evidence?
  • · Replies 6 ·
Replies
6
Views
7K
Undergrad How can an expanding Universe look homogeneous?
  • · Replies 27 ·
Replies
27
Views
4K
Graduate Abundance and mass spectrum of PBH
  • · Replies 3 ·
Replies
3
Views
1K
High School [Curiosity] Are there any central databases of Red Shift?
  • · Replies 2 ·
Replies
2
Views
1K
Graduate Why the fine-tuning argument for improbable existence is a fallacy
  • · Replies 13 ·
Replies
13
Views
3K
High School Could accelerating expansion be caused by a "spinning" universe?
  • · Replies 14 ·
Replies
14
Views
2K
Undergrad Can black hole studies shed any light on dark matter
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Is the Divisor (2π)^3 Necessary in Photon Gas Equations?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Dark Plasma charged under unbroken U(1)' gauge interaction
  • · Replies 1 ·
Replies
1
Views
1K
Insights How to Create a Universe - Instructions for an Apprentice God - Comments
  • · Replies 14 ·
Replies
14
Views
3K
Undergrad What is the definition of the entropy of the Universe?
  • · Replies 7 ·
Replies
7
Views
3K
Undergrad What would the universe look like without dark matter?
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Does the Friedmann vacuum equation have a linear solution?
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Expanding universe needs a big bang?
  • · Replies 101 ·
4
Replies
101
Views
9K
Undergrad Why can't LIGO detect collisions of super massive black holes?
  • · Replies 16 ·
Replies
16
Views
2K
Undergrad Is the Minkowksi/Einstein Block Universe theory science?
  • · Replies 8 ·
Replies
8
Views
5K
High School 83 quasars right up against the Event Horizon
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad What would a big crunch look like observationally?
  • · Replies 4 ·
Replies
4
Views
2K
High School How to explain "the right hand rule" to an alien universe
  • · Replies 15 ·
Replies
15
Views
5K
Undergrad Exponential expansion and the Cosmological Constant
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Imaging galaxies receding at a velocity that exceeds c?
  • · Replies 12 ·
Replies
12
Views
4K
High School What is the most common/likely process of the Universe?
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Covariance matrix size: 3x3 or 4x4?
  • · Replies 5 ·
Replies
5
Views
2K
Graduate CMB as thermal radiation of cosmic dust?
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad How does Hawking radiation contribute to the formation of new stars?
  • · Replies 28 ·
Replies
28
Views
5K
Graduate Classical scalar field as Dark Matter
  • · Replies 14 ·
Replies
14
Views
3K
Undergrad Fine tuning and the multiverse
  • · Replies 6 ·
Replies
6
Views
3K
Graduate Cosmological fluctuations (Weinberg's cosmology, p. 284)
  • · Replies 10 ·
Replies
10
Views
3K
High School What is the 'proof' of the no-hair theorem of black holes?
  • · Replies 5 ·
Replies
5
Views
3K
High School CMBR: Is It Constant or Changing Over Time?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Cross-correlations: what size to select for the matrix?
  • · Replies 4 ·
Replies
4
Views
2K
Graduate Dark matter and the fabric of space time,
  • · Replies 2 ·
Replies
2
Views
2K
High School Which Hawking paper? (no singularity at the beginning of the universe)
  • · Replies 2 ·
Replies
2
Views
3K
Graduate Is "Broken Symmetry" truly foundational?
  • · Replies 4 ·
Replies
4
Views
2K
Graduate Decoupling of SVT Metric Perturbations
  • · Replies 2 ·
Replies
2
Views
2K
High School Help with when expansion acceleration began
  • · Replies 23 ·
Replies
23
Views
4K
High School Can a single photon make up a universe?
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Why ##\omega=0## for a matter dominated universe?
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Is a "collision" of galaxies noticeable on a planetary scale
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Expansion of positively and negatively curved universe
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad Variable Dark Energy: Would P Remain Constant?
  • · Replies 17 ·
Replies
17
Views
3K
Undergrad Is Something Missing in the Expansion of Our Flat Universe?
  • · Replies 17 ·
Replies
17
Views
2K
High School What Happens at the Event Horizon of a Black Hole?
  • · Replies 5 ·
Replies
5
Views
2K
High School Andromeda Collision VS Expansion
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad New Problems I have with Dark Matter
  • · Replies 13 ·
Replies
13
Views
3K
Undergrad What Is the Singularity and Its Role in the Big Bang?
  • · Replies 26 ·
Replies
26
Views
4K
Undergrad Difference between dark energy and dark matter
  • · Replies 6 ·
Replies
6
Views
2K
High School How exactly inflation solves the Horizon Problem
  • · Replies 13 ·
Replies
13
Views
4K
Undergrad Relative Amount of Hydrogen in the Universe
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad Inflation resolves the horizon problem
  • · Replies 7 ·
Replies
7
Views
2K
High School Naked Singularity, Black hole mass limit
  • · Replies 12 ·
Replies
12
Views
2K
Undergrad Supermassive singularity the cause of the Big Bang?
  • · Replies 32 ·
2
Replies
32
Views
4K
Undergrad The Universe as an isolated system
  • · Replies 27 ·
Replies
27
Views
4K
Undergrad Dark energy and the rotation curve of spiral galaxies
  • · Replies 1 ·
Replies
1
Views
1K
High School Active galaxies point to new physics of cosmic expansion
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Inflation and the size of the Universe
  • · Replies 9 ·
Replies
9
Views
3K
Undergrad What is the Hubble Parameter over time and how can I calculate it?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Luminosity Distance: Finding the Connection
  • · Replies 15 ·
Replies
15
Views
3K
High School Algebraic Topology in the tv show The Big Bang Theory
  • · Replies 11 ·
Replies
11
Views
21K
Undergrad Relationship between Energy density and Curvature
  • · Replies 27 ·
Replies
27
Views
5K
Undergrad Sachs-Wolfe effect and Superclusters/Supervoids
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Relativistic Reference Frames and the Big Bang?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad What Are the Boundaries of a Flat and Saddle-Shaped Universe?
  • · Replies 24 ·
Replies
24
Views
4K
Undergrad What are the latest thoughts about the timescape cosmology
  • · Replies 12 ·
Replies
12
Views
5K
Undergrad Theory behind how expansion moves mass but doesn't interfere with inertia?
  • · Replies 21 ·
Replies
21
Views
3K
High School Comoving distance in cosmology
  • · Replies 1 ·
Replies
1
Views
2K
High School Do Black holes reach a critical mass?
  • · Replies 3 ·
Replies
3
Views
3K
Graduate Hot dark matter constrained by the CMB
  • · Replies 7 ·
Replies
7
Views
3K
High School Missing Dark Matter of NGC1052-DF2
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad Why does an Empty Universe have to obey Negative Curvature?
  • · Replies 10 ·
Replies
10
Views
3K
Undergrad Event Horizon and Particle Horizon
  • · Replies 12 ·
Replies
12
Views
4K
High School Ratio between the sizes of the Observed and the Entire Universe
  • · Replies 7 ·
Replies
7
Views
3K
Undergrad Confusion about the math of the Comoving Coordinates
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad Metric of the Universe and dependence on Cosmological P
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Unification of dark energy and dark matter
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Could Our Universe Be a Mirror Image of an Antimatter Universe?
  • · Replies 6 ·
Replies
6
Views
2K
High School The k term in the Friedmann equation
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad The Expanding Universe and a stationary frame of reference
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Footnote on page 151 of Weinberg's Cosmology book
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Is there any evidence of a universe expansion jerk
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Calculating dark energy and matter density
  • · Replies 18 ·
Replies
18
Views
3K
Undergrad Curvature of space in large regions: zero or not?
  • · Replies 9 ·
Replies
9
Views
2K
High School Galaxy Collisions & Expansion: What's Going On?
  • · Replies 3 ·
Replies
3
Views
2K