What is the minimal size of our Universe?

The Universe is at least 137 billion light-years wide (42 Gpc), new study from Oxford astronomers showed (arXiv:1101.5476). Compared to more traditional statistical techniques they got that the Universe is at least 200 billion light-years wide, which means that it is actually 50 Billion light years bigger than previously estimated. However, the new statistical method didn’t force it’s own preference on the shape of the Universe via specifically chosen prior parameters, thus it is possible to set 137 Billion light-years as the smallest lower limit on the size of the Universe.

The study also showed that the most likely Universe is the Universe predicted by Einstein, and has flat geometry and cosmological constant. We would like to remind the readers that  Einstein introduced cosmological constant to make the Universe static, while later he rejected the idea in favor of dynamic universe. However, modern astronomers found that the Universe expands with acceleration, thus they introduced the cosmological constant again to make universe expand with acceleration and called it the Dark Energy.

As far as the rumor goes American astronomers used the term DARK ENERGY to convince the  U.S. department of energy to invest into the research, the strategy proved to work out well. Many experiments came out to test dark energy, including WMAPSDSS2dFPanSTARRS and etc.

This estimate of the size comes from the newest data from Cosmic Microwave BackgroundType Ia Supernovae, and exact positions of  galaxiesmeasure in the last 3 years. The Oxford scientists   applied new statistical algorithms to compare possible cosmological models and averaged all the results across all possible combination of cosmological models, thus eliminating the model’s uncertainty.

The cosmos is 13.7bn years old (you can check it yourself here http://icosmos.co.uk) but the expansion of space after the Big Bang means that simple distance measurements do not apply. This means that the first light reaching us from the earliest Universe has been traveling for more than 13 billion years. But it is wrong to assume  that the radius of the Universe is 13.7 billion light-years and that it is 27.4 billion light-years wide, as the Universe has been expanding ever since the Big Bang when energy, space and time itself began.

According to Mihran Vardanyan of Oxford University, UK, and colleagues writing in the journal Monthly Notices of the Royal Astronomical Society – Letters (arXiv:1101.5476), the distance that light traveled in the early Universe is increased by its overall expansion and it’s possible to estimate the lower bound of the size of the Universe.
They applied new Bayesian statistical technique, to perform the complex analysis. The new technique allowed to perform computationally heavy model comparison in a much more efficient way.  The study was presented at several Universities, including OxfordUCLINAF and etc.

We have also previously written about the teams previous works, which covered the best possible future estimates on the curvature of the Universe as well as on the best observational strategies to understand the Dark Energy and Curvature.

BIO: In 2005 Mihran graduated from Yerevan State University Physics department with Bachelors degree in Theoretical Physics. In 2006 Mihran was invited to continue his education at the University of Oxford as a D.Phil student, working on advanced statistical methods in Cosmology. He developed new statistical techniques to compere cosmological models, forecast future results of cosmological experiments and derive possible limits on reconstruction of cosmic curvature. He is the author of one of the most popular online cosmology calculators: iCosmos.co.uk.

In 2007 Mihran co-funded Oxford University Armenian Society – currently he is the President of the society. He organized many events to promote Armenian culture, regular Armenian language classes, Armenian film showings, and joint social events with other Oxford societies. Also he founded the society’s library.

During his time at Oxford Mihran has co-founded Get-Inspired.org project that aims to encourage talented students from disadvantaged regions, to realize their full potential and go to study at the leading universities abroad. He is also the leader and organizer of the Oxford University Expedition to Qarahunge. The expedition has been approved and supported by Oxford University Expedition Council and Royal Geographical Society.  After the expedition Qarahunge has been featured on H1, Voice of America, CNN, CBS, History Channel US and etc. This proved to be one of the biggest promotional campaigns for Syunik Province.

Publish Date
February 02, 2011