Early dark energy could resolve cosmology’s two biggest puzzles

Dark matter/energy were in the news again recently! See also my blog post here about dark matter.

What is the difference between speculation and science?

The so called Big Bang is another one of those speculations!

"A new study ... proposes that a mysterious force known as early dark energy could solve two of the biggest puzzles in cosmology and fill in some major gaps in our understanding of how the early universe evolved.

One puzzle in question is the “Hubble tension,” which refers to a mismatch in measurements of how fast the universe is expanding. The other involves observations of numerous early, bright galaxies that existed at a time when the early universe should have been much less populated.

Now, the MIT team has found that both puzzles could be resolved if the early universe had one extra, fleeting ingredient: early dark energy. Dark energy is an unknown form of energy that physicists suspect is driving the expansion of the universe today. Early dark energy is a similar, hypothetical phenomenon that may have made only a brief appearance, influencing the expansion of the universe in its first moments before disappearing entirely. ..."

From the abstract (abstract contains images):

"JWST has revealed a large population of UV-bright galaxies at [] 

 and possibly overly massive galaxies at ⁠[], challenging standard galaxy formation models in the ΛCDM cosmology. We use an empirical galaxy formation model to explore the potential of alleviating these tensions through an Early Dark Energy (EDE) model, originally proposed to solve the Hubble tension. Our benchmark model demonstrates excellent agreement with the UV luminosity functions (UVLFs) at in both ΛCDM and EDE cosmologies. In the EDE cosmology, the UVLF measurements at  based on spectroscopically confirmed galaxies (eight galaxies at ⁠) exhibit no tension with the benchmark model. Photometric constraints at  can be fully explained within EDE via either moderately increased star-formation efficiencies (⁠ at ⁠) or enhanced UV variabilities (⁠ mag at ⁠) that are within the scatter of hydrodynamical simulation predictions. A similar agreement is difficult to achieve in CDM, especially at ⁠, where the required 

 exceeds the maximum value seen in simulations. Furthermore, the implausibly large cosmic stellar mass densities inferred from some JWST observations are no longer in tension with cosmology when the EDE is considered. Our findings highlight EDE as an intriguing unified solution to a fundamental problem in cosmology and the recent tensions raised by JWST observations. Data at the highest redshifts reached by JWST will be crucial for differentiating modified galaxy formation physics from new cosmological physics."

Study: Early dark energy could resolve cosmology’s two biggest puzzles | MIT News | Massachusetts Institute of Technology "In the universe’s first billion years, this brief and mysterious force could have produced more bright galaxies than theory predicts."

Early galaxies and early dark energy: a unified solution to the hubble tension and puzzles of massive bright galaxies revealed by JWST (open access)

Early dark energy could have triggered the formation of numerous bright galaxies, very early in the universe, a new study finds. The mysterious unknown force could have caused early seeds of galaxies (depicted at left) to sprout many more bright galaxies (at right) than theory predicts.