Ruth Gregory

Contact numbers (Country code 44, omit the 0):

0191 334 3092 (Maths)
0191 334 3761 (Physics)

Research Interests

My research centres on the interface between fundamental high energy physics and cosmology. Physics explains how nature works, and we generally use it to tell us what will (or at the quantum level what is most likely!) to happen in a given situation. Cosmology is the study of the universe, and seeks to explain what we see through our telescopes. What makes the study of particle cosmology so interesting is that we attempt to use physics we have not and can not test in the lab (the energies involved are simply too high) to answer the most fundamental question of all - how did our universe begin?

One of the more exciting recent developments is this field is that of the braneworld scenario. In this, we are akin to "flatlanders", living in our four-dimensional universe which is a sheet (or brane) within a higher dimensional world. These extra dimensions can be relatively large (on the order of the thickness of a thread) yet remain hidden because we are stuck on our "world-sheet", the only clues they leave are very subtle inconsistencies in our own physical world.

My recent work has been to try to explore simple models of these braneworlds, and to see what physical features they can possibly have. For example, a deceptively simple modification of the original braneworld model gives a very curious law for gravitation. A generic feature of these hidden extra dimensions is that they show up as inconsistencies in Newton's Law of gravitation at small distances - as you might expect if you are giving gravity a few extra places to go on the small scale! However, what was curious about the model put forward by myself and collaborators Rubakov and Sibiryakov, was that our gravity was not only different on the small scale, but also on the very very large scale - distances comparable to the size of our universe! It might seem that this would be in conflict with what we know about our universe - yet recent astronomical observations from the Hubble Space telescope have revolutionized our understanding of the universe: we either have modification of gravity at very large distances, or a mysterious "dark energy", the so-called cosmological constant. Unfortunately, our model turned out not to be a viable theory of gravity as it suffered from unpleasant side-effects, however, I am still looking for other cosmological models - including those motivated from string theory, and trying to understand the more subtle structure of the ones we have.

Whether the apple falls according to Newton and Einstein, or whether gravity turns out to be something rather more exotic, either way - we have a challenge for cosmology!

  • List of publications from HEP-SPIRES-SLAC
  • Black Holes : A lecture to 6th Formers
  • Matrix Theory
  • EPSRC grant summary

    Meetings Organized

    Occasionally I help organize conferences, workshops or small meetings. Here is a list of ones at Durham:

  • UK Cosmology meeting in September 2005
  • Theory and Experiment in Quantum Gravity-March 2005
  • The Origin of the Primordial Density Perturbation-March 2005
  • Post-Strings 2004
  • COSMO-03: 7th International Workshop on Particle Physics and the Early Universe
  • Pre-Strings 2002
  • UK Cosmology meeting in September 2000
  • UK Theory meetings (occasionally)


    I teach in both the Maths and Physics Departments, which is twice the fun - but twice the admin! In addition, for the next three years I am on secondment to Perimeter Institute in Canada, and will be teaching in the PSI program there.

    ACADEMIC YEAR 2010-11  

    Other Professional Interests

    As well as my work in Durham I am, or have been, also involved with other physics-related issues.

  • Implementation Group for Women in SET
  • Editorial Board Member for Classical and Quantum Gravity
  • Treasurer of Mathematical and Theoretical Physics Group of the Institute for Physics