Five years ago, the Nobel Prize in Physics was awarded to three astronomers for their discovery, in the late 1990s, that the universe is expanding at an accelerating pace. Now, a team of scientists led by Professor Subir Sarkar of Oxford University’s Department of Physics has cast doubt on this standard cosmological concept.
Researchers from the University of Cambridge and Queen Mary University of London have shown how a bizarrely shaped black hole could cause Einstein’s general theory of relativity, a foundation of modern physics, to break down. However, such an object could only exist in a universe with five or more dimensions.
The Big Bang Theory with its early period of exponential growth known as inflation is the prevailing scientific model for our universe, in which the entirety of space and time ballooned out from a very hot, very dense point into a homogeneous and ever-expanding vastness. This theory accounts for many of the physical phenomena we observe, but what if that’s not all there was to it?
A Lawrence Livermore National Laboratory team has combined theoretical and computational physics techniques using the Laboratory’s 2-petaflop Vulcan supercomputer to devise a new model of dark matter. They found that dark matter is “stealthy” today, but would have been easy to detect in the extremely high-temperature plasma conditions that pervaded the early universe.
The Royal Astronomical Society’s National Astronomy Meeting 2015 in Llandudno, Wales, 5—9 July
is the largest regular professional astronomy event in the UK and will see leading researchers from around the world presenting the latest work in a variety of fields. Kulvinder Singh Chadha reports from the conference.
A new study finds that elliptical galaxies maintain a remarkably constant circular speed out to large distances from their centres, in the same way that spiral galaxies do. In these very different types of galaxies, stars and dark matter somehow conspire to redistribute themselves to produce this effect, or does modified Newtonian dynamics offer an explanation?