New Hubble’s constant shows local universe is expanding even faster than we thought

If you feel like everything has been getting faster lately, you’re not alone.

Astrophysicists, including Brad Tucker at the Australian National University, have calculated the most accurate measurement yet for the expansion rate of the nearby universe.

They’ve found that in our little corner of the cosmos everything is flying apart quite a bit quicker than we’ve previously thought.

more…

What would make the expansion of the universe speed up or is it a case that the calculations were incorrect only?

For example, currently as the process of the universe expansion takes place can that also mean that as the density of the clumping of planets and stars thins out ( bad wording) , does the changes in gravitational fields mean there is a local event of an increase of the expansion rate but overall the expansion rate of the outer limits are the same expansion rate (hubble’s constant)? Is this in part due to the local and viewable galaxy measured being affected by the lessening gravitational fields between objects contained in the observed and measurable universe?

I think its to do with the local group of galaxies being less dense than elsewhere

Professor Geraint Lewis at the University of Sydney said the higher Hubble constant for the local universe could indicate a lower density of matter. Professor Lewis, who was not connected with the research, said explanations for the local anomaly are nothing more than informed speculation.

but says its speculation

so it might be something else

Dark radiation may be causing universe to expand faster than expected

CrazyNeutrino said:

New Hubble’s constant shows local universe is expanding even faster than we thought

If you feel like everything has been getting faster lately, you’re not alone.

Astrophysicists, including Brad Tucker at the Australian National University, have calculated the most accurate measurement yet for the expansion rate of the nearby universe.

They’ve found that in our little corner of the cosmos everything is flying apart quite a bit quicker than we’ve previously thought.

more…

“ Using the Hubble Space Telescope, the international team of 15 physicists measured the movements of 2400 Cepheid variable stars and 300 type 1a supernovae in 22 nearby galaxies to show that the local universe is expanding at the rate of 73.2 kilometres a second for every megaparsec of distance. A megaparsec is 3.26 million light years and is an accepted limit for the “local” universe.
The Hubble constant for the whole universe, based on calculations from the remnant energy of the Big Bang, is 69.3 kilometres a second for every megaparsec of distance, according to NASA.”

Hmm. It isn’t as if there haven’t been hundreds of measurements of the Hubble constant before. IIRC, Hubble originally measured about 200 km/s. There were wars over the value of the Hubble constant. But still worth looking into.

From NASA

WMAP AND THE HUBBLE CONSTANT

By characterizing the detailed structure of the cosmic microwave background fluctuations, WMAP has accurately determined the basic cosmological parameters, including the Hubble constant. The current best direct measurement of the Hubble constant is 73.8 km/sec/Mpc (give or take 2.4 km/sec/Mpc including, both random and systematic errors), corresponding to a 3% uncertainty. Using only WMAP data, the Hubble constant is estimated to be 70.0 km/sec/Mpc (give or take 2.2 km/sec/Mpc), also a 3% measurement. This assumes that the universe is spatially flat, which is consistent with all available data. This measurement is completely independent of traditional measurements using Cepheid variables and other techniques. However, if we do not make an assumption of flatness, we can combine WMAP data with other cosmological data to get 69.3 km/sec/Mpc (give or take 0.8 km/sec/Mpc), a 1% solution that combines different kinds of measurements. After noting that independent observations give consistent results, it is reasonable to combine information to get the best estimate of parameters.
———
So the new estimate from the local universe of 73.2 is actually closer than the earlier estimate from the local universe of 73.8.

Uncertainty of Hubble constant in local universe reduced from 3.3% to 2.4%.

The number of Cepheid-calibrated Type 1a supernovae has increased from 8 to 19.

Excellent work.

This paper is directly relevant.
Reconciling Planck with the local value of H0

CrazyNeutrino said:

New Hubble’s constant shows local universe is expanding even faster than we thought

If you feel like everything has been getting faster lately, you’re not alone.

Astrophysicists, including Brad Tucker at the Australian National University, have calculated the most accurate measurement yet for the expansion rate of the nearby universe.

They’ve found that in our little corner of the cosmos everything is flying apart quite a bit quicker than we’ve previously thought.

more…

The latest apod discusses this.
http://apod.nasa.gov/apod/ap160606.html

Image The Supernova and Cepheids of Spiral Galaxy UGC 9391.