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Lasenby Symposium

When Jul 01, 2014
from 02:00 PM to 06:30 PM
Where Kavli Institute for Cosmology, Cambridge
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KICC is hosting a half-day symposium in celebration of the 60th birthday of Anthony Lasenby. Anthony has made significant contributions across an unusually broad range of topics in physics and astronomy. Five talks by Anthony's colleagues, including his Ph.D. supervisor (Prof. Rod Davies) and three of his former Ph.D. students, will survey some of Anthony's main research interests: cosmic microwave background, the Galactic centre, physical applications of geometric algebra, and gravitational physics.




Rodney Davies
University of Manchester

Early CMB Anisotropy Measurements

Anthony Lasenby came into the CMB field at an exciting time.  The 3K radiation had been decisively detected.  The 3 mK dipole was also well-defined.  The anisotropy search was at its most active.  Sea-level sites were found to be inadequate and accordingly mountain sites with low water vapour levels were at a premium.    After preliminary observations at Jodrell Bank the Manchester University team chose to collaborate with the Instituto de Astrofisica de Canarias at the Izana site on Tenerife for their successful beam-switch and interferometric searches.  They were later joined by the Cambridge group in the Very Small Array project which obtained one of the earliest convincing power spectra of CMB fluctuations.  Anthony had a pivotal role in the data analysis and the interpretation of these various projects.  This has led to his substantial involvement in the Planck satellite which is the foremost CMB experiment.


Antony Lewis
University of Sussex

Rayleigh Scattering: Blue Sky Thinking for Future CMB Observations

Planck and other CMB experiments have measured the nearly-blackbody CMB spectrum to high accuracy. Future observations may be able to probe frequency dependence, in particular Rayleigh scattering from neutral hydrogen has a distinctive signature at high frequencies and should be observable before too long. I'll discuss the origin of the signal and what it might be useful for.


Jennifer Hatchell
University of Exeter

The Galactic Centre

I will present an onlooker's tour of Galactic Centre research, including recent results, historical context, and local interest.  The centre of the Galaxy hosts many of the most extreme astrophysical phenomena in the Milky Way, including the supermassive black hole Sgr A*, starburst clusters, and magnetic filaments.  Its veiled delights attracted optical astronomers in the 1920s, were revealed by the new radio and infrared astronomy in the 1950s and 60s, and are still top attractions in the 21st century golden age of astronomy.  In the early 1990s, Anthony Lasenby saw the potential and was pulled into Galactic Centre research, setting the future direction for two PhD students, one of whom will be giving this talk.


Chris Doran
University of Cambridge

Geometric Algebra and the Video Game Industry

In 2005 Dr Chris Doran stepped out from an (arguably) promising research career to set up a company developing graphics technology for the videogames industry. The company, Geomerics, went on to be involved in some of the largest game titles in history, including the Need for Speed and Battlefield franchises. In December 2013 Geomerics was acquired by the Cambridge-based IP and design company ARM. In this talk Dr Doran discusses how to bridge the gap between mathematics and product, and where the interesting new challenges lie for real-time graphics and entertainment. 


Sam Dolan
University of Sheffield

Black Holes, Bound States and Instabilities

'A black hole has no hair,' proposed John Wheeler in 1973, summarizing the standard view that black holes have just three 'bald' characteristics - mass, electric charge and angular momentum - as all other information is soon lost behind the black-hole event horizon. In this talk, I will explore the possiblity that perhaps 'black holes are hirsute'.  As shown by Prof. Lasenby and colleagues, black holes may form bound states with massive fields. If there exist in nature ultra-light bosonic fields, such as axions, with a rest mass such that the Compton wavelength is comparable to the black hole horizon radius, then the hair of a black hole may grow back exponentially. Rapid hair growth is promoted by a phenomenon known as superradiance: the stimulated extraction of rotational energy from a black hole. Through a variety of simulations I will explore this radical cure for black hole baldness, and I'll describe some recent interesting work on possible end-points for the instability.