Utah State University

Physics Colloquium

 

The Howard L. Blood Scholarship

RecipientsÕ Research, Section II

 

Sam Barkat, Juan Trujillo

Physics Department, Utah State University

 

 

Creating a Database of Einstein Exact Solution in Maple       Sam Barkat

I will review the historical development of ideas which led to Einstein's theory of gravity. In Einstein's theory, gravitational fields are determined by matter and energy distributions according to an extremely complicated system of non-linear partial differential equations known as the Einstein equations.  Despite their complexity, a large number of solutions are known to these equations, corresponding to a wide variety of physical situations.  I will report on on-going research to use computer algebra methods to analyze these solutions and develop a comprehensive database of them.

 

A Wave Equation in Biconformal Space       Juan T. Trujillo

 

Just as the symmetry group of Newtonian mechanics, which is the group of translations and rotations, and the symmetry group of relativity, which comprises the PoincarŽ group (the group of Lorentz transformations and translations), the conformal group seems to be an accurate and more complete symmetry group of the universe (comprising not only the subgroups already mentioned, but also the group of special conformal transformations and the group of dilatations).  Noting that Dirac was able to write the Dirac equation, notably by taking the square root of the Klein-Gordon equation, we attempted, first of all, to find a wave equation based on the conformal group by forming a Casimir operator—an operator that commutes with every generator (infinitesimal operator) of the conformal group—by  choosing a representation of the generators that included not only generalized coordinates, but also generalized momenta.  In effect, by ÒsquaringÓ these generators, we were able to arrive at one such equation that treated the generalized coordinates and the generalized momenta on an equal basis.  Our next approach, was to form the generalized Klein-Gordon equation by noticing that biconformal space—the conformal group gauged by the Lorentz transformations—has an induced metric formed by the dual forms of the generators of translations and special conformal transformations as given by the Maurer-Cartan equations.  From this particular choice of the induced metric, we were able to form an eight-dimensional Laplacian using differential form operators.  Since both of these operators, or equations, only had second order terms, we attempted to find the Òsquare rootÓ of them by trying to find two linear operators such that when applied twice, yielded the original operator.  In doing so, we had to attempt to satisfy simultaneously six equations.  We were able to come up with a solution for an orthonormal induced metric.

Tuesday, September 9, 2008

3:30 pm

SER BLDG, Room 244

 

 

Reception at 3:00 pm

SER BLDG, Room 244