Hubble Tension tagged posts

When it comes to measuring how fast the Universe is expanding, the result depends on which side of the Universe you start from. A recent study has calibrated the best cosmic yardsticks to unprecedented accuracy, shedding new light on what’s known as the Hubble tension.

The Universe is expanding — but how fast exactly? The answer appears to depend on whether you estimate the cosmic expansion rate — referred to as the Hubble’s constant, or H0 — based on the echo of the Big Bang (the cosmic microwave background, or CMB) or you measure H0 directly based on today’s stars and galaxies. This problem, known as the Hubble tension, has puzzled astrophysicists and cosmologists around the world.

A study carrie...

A research team led by Dr. Prabhakar Tiwari from the National Astronomical Observatories of Chinese Academy of Sciences (NAOC) has found that superhorizon modes could explain the observed Hubble tension.

Their findings were published in The Astrophysical Journal Letters on Jan. 18.

It is generally believed that the universe is isotropic and homogeneous on large distance scales. This hypothesis forms the basis of the standard Big Bang cosmology, called the cosmological principle (CP)...

A new analysis of the Hubble constant to show that the Gaussian Processes data reconstruction technique may not actually be independent of all cosmological models — and that it may be time to question the validity of model independence itself.

The technique of Gaussian Processes (GP) is widely used to reconstruct cosmological parameters, most notably the expansion rate of the universe, using observational data. For many cosmologists, the crowning achievement of this approach is its ‘model independence’ — meaning it can be applied universally across all models...