Monthly Archives: February 2016

2016 Bergmann-Wheeler Thesis Prize winner: Lisa Glaser

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Lisa Glaser

Lisa Glaser is currently a Research Fellow at University of Nottingham, and will (from September 2016) join Renate Loll’s group at the Radboud Universitet in Nijmegen with a Marie Skłodowska-Curie fellowship to explore renormalisation in discrete theories of quantum gravity.
You can follow her on Twitter. 

1. Tell us about your thesis

During my Ph.D. I worked on causal dynamical triangulations and causal set theory. While these approaches are very different at first sight, upon closer examination they show important similarities. In both theories we try to solve the path integral over geometries by introducing a regularisation.

In causal dynamical triangulations the regularisation are simplices, which scale away in the continuum limit, while causal set theory proposes a fundamental smallest volume of space-time events. Another similarity is that both of these theories try to incorporate the Lorentzian structure of space-time into the theory. In causal dynamical triangulations this is implemented through a Continue reading →

The importance of being Melvin

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The authors, Jennie Traschen and David Kastor, enjoy the wit and humor of Oscar Wilde.

The authors, Jennie Traschen and David Kastor, enjoy the wit and humor of Oscar Wilde. The image above has been obtained from the Wikimedia website, where it is stated to have been released into the public domain. It is included within this blog post on that basis.

Like Oscar Wilde’s famous 1895 play, our recent CQG article “Melvin Magnetic Fluxtube/Cosmology Correspondence,” features an intricate interplay of dual and concealed identities. While our paper lacks the biting wit of Wilde’s dialogue, e.g.

“I do not approve of anything that tampers with natural ignorance. Ignorance is like a delicate exotic fruit; touch it and the bloom is gone. The whole theory of modern education is radically unsound. Fortunately in England, at any rate, education produces no effect whatsoever,”

our revelations regarding true identity do play out on a more vast, indeed a cosmic stage.

Melvin’s solution to the Einstein-Maxwell equations describes a static bundle of magnetic flux-lines bound together by self-gravity. Originally discovered in 1963, it has a rich and influential history. In 1964, Thorne studied the stability of what he called “Melvin’s Magnetic Universe.” Its resistance to gravitational collapse was an important clue leading to the formulation of his well-known hoop conjecture. In 1975, Ernst showed that Continue reading →

Gravitational waves detected. Einstein was right … again

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Clifford Will

Clifford Will is the Editor-in-Chief of Classical and Quantum Gravity

As if celebrating the 100th birthday of general relativity weren’t enough, the LIGO-Virgo collaboration has provided “the icing on the cake” with today’s announcement of the first direct detection of gravitational waves. At press conferences in the USA and Europe, and in a paper in Physical Review Letters published afterward, the team announced the detection of a signal from a system of two merging black holes.

The signal arrived on 14 September, 2015 (its official designation is GW150914), and was detected by both the Hanford and Livingston advanced detectors of the LIGO observatory (the advanced Virgo instrument in Italy is not yet online). It was detected first by Continue reading →