Richard Feynman

Richard Feynman: Simulating Physics with Computers

Richard Feynman is known in various circles as a quantumtheoretical physicist, engineer, samba drummer, nobel prize winner, lock picker, radio repairer, and all around curious character. In this paper, we examine a keynote address at the California Institute of Technology in May 19811 in which he proposes the idea of a computer that could act as a quantum mechanical simulator[?]. As we will dis...

Feynman diagrams versus Fermi-gas Feynman emulator

Remembering Richard [Obituary, Richard A.Newton]

Supermanifolds from Feynman graphs

We generalize the computation of Feynman integrals of log divergent graphs in terms of the Kirchhoff polynomial to the case of graphs with both fermionic and bosonic edges, to which we assign a set of ordinary and Grassmann variables. This procedure gives a computation of the Feynman integrals in terms of a period on a supermanifold, for graphs admitting a basis of the first homology satisfying...

The Feynman-Kac formula

where ∆ is the Laplace operator. Here σ > 0 is a constant (the diffusion constant). It has dimensions of distance squared over time, so H0 has dimensions of inverse time. The operator exp(−tH0) for t > 0 is an self-adjoint integral operator, which gives the solution of the heat or diffusion equation. Here t is the time parameter. It is easy to solve for this operator by Fourier transforms. Sinc...