Schrödinger
code: Quantum mechanics is a fundamental in physics describing the
evolution of non-relativistic quantum systems. In this webpage, I solve
the time-dependent Schrödinger equation using the Suzuki-Trotter method.
I illustrate the code with a one- and two-dimensional example.
Picard-Lefschetz code:
Oscillatory integrals are fundamental to physics but subtle to define
and often difficult to evaluate. Using Picard-Lefschetz theory, I
develop a new method to evaluate multi-dimensional oscillatory
integrals. The code is demonstrated with several lensing problems in
wave optics.
DTFE: Delaunay
Tesselation Field Estimator (DTFE) is a mathematical tool for the
reconstruction of the density and velocity field of a discrete point set
developed by Willem Schaap and Rien van de Weijgaert
(Schaap
and Weijgaert 2004,
Willem
Schaap 2007).
Catastrophe theory: Catastrophe theory is the classification of
degenerate critical points. In these notes I give an impression of the
mathematics underlying Catastrophe theory following
Catastrophe
Theory by Domenico Castrigiano and Sandra Hayes.
Topological
Galois theory: I prove the famous unsolvability of polynomials with
degree higher than \(4\) using
topological Galois theory. The discussion is based on an elementary
proof developed Vladimir I. Arnol’d in a lecture series for high school
students in 1963. For the original proof see the transcript of the
lecture series
Abel’s
Theorem in Problems and Solutions. The notes are also based on the
review paper by
Henryk Żolądek and the talk by
Michael O’Connor.
Fig. 5 - The trajectories of the roots (right) under a loop in function
space (left)
Gaussian
Random Field Theory: I introduce a couple of key points in Gaussian
random field theory and its applications to cosmology.
Fig. 6 - Gaussian random fields: the primordial density field (right)
and gravitational potential (left)
One-piece
Cody kite: In the nineteenth century
Samuel
Franklin Cody developed the Cody War-Kites, which were
large kites able to lift persons to great hight, and were used by the
British before World War I as a smaller alternative to balloons for
artillery spotting. More recently, Ton Vinken developed an adaptation of
the Cody kite which can be constructed out of a single piece of
material. Unfortunately, it is currently difficult to find plans online.
Inspired by this idea, I constructed a plan which I hope will encourage
others to build the one-piece Cody kite.