Contents

1. Minutiae (Password Protected Page)

2. Overview of Sturm-Liouville theory: the maths behind quantum mechanics

3. Maple code for quantum scattering from an Eckart potential

4. The p-adic number field as a completion of the rationals

5. Topological equivalence of the 2-sphere and the extended complex plane

6. Pythagorean triples in a stereographic projection

7. Gauss’s flux theorem for gravity, Poisson’s equation and Newton’s law

8. Brownian motion and fractional Brownian motion: self-similar processes

9. Applying Chebyshev’s inequality and Borel-Cantelli lemma to Brownian motion

10. A variant of Einstein’s partial differential equation for Brownian motion

11. A division algorithm for converting prime reciprocals into ternary numbers

12. A note on the quaternion rotation operator

13. Different branch cuts for the principal argument, log and square root functions

14. On classifying singularities, with a quick look at a Schwarzschild black hole

15. Matrix calculus approach to changing variables in Laplace’s equation

16. Changing variables in the square of the angular momentum operator

17. Variational setups yielding Newton’s second law and Schrödinger’s equation

18. Alternative approaches to formulating geodesic equations on manifolds

19. Proving Noether’s theorem

20. Invariance under rotations in space and conservation of angular momentum

21. Dirichlet character tables up to mod 11

22. Overview of the Lie theory of rotations

23. Solving Schrödinger’s equation by B-spline collocation

24. Proving the relativistic rotation paradox

25. Decomposition of Lorentz transformations using orthogonal matrices 

26. Classical and quantum harmonic oscillators

27. A scale-free probability distribution must be a power law

28. A simple Yule-Simon process and Zipf’s law

29. Approximating logarithms of large numbers

30. From random walk to Brownian motion with drift

31. Strange notations in mathematical probability

32. A couple of results involving the beta function

33. Useful methods in Laplace transform theory

34. Quick way to explain the concept of a solid angle

35. Some mathematics relating to phonons

36. Free particle in a ring with a periodic boundary condition

37. Bra-ket formalism of quantum mechanical measurement

38. Differentiating a double integral with respect to its upper limits

39. Markov’s inequality and the Cramér-Chernoff bounding method

40. The role of the Legendre transform in large deviation theory

41. Two versions of the exponential cumulant generating function

42. Inverse Fourier transform of a characteristic function

43. Applying the Bromwich integral to a cumulant generating function

44. Using an asymptotic approximation to obtain a closed form solution

45. Using Lagrange’s interpolation formula to prove complicated sum/product identities

46. A Phys. Rev. Letter by M Wilkinson on large deviation analysis of rapid-onset rainfall

47. Accurate analytical approximation formulae for large-deviation analysis of rainfall

48. A note on mathematics in Latin

49. Monomer injections leading to oscillatory behaviour in a model of rain formation

50. Study of a Lagrangian function approach to analysing raindrop growth

51. A spline approximation scheme for large deviation theory problems

52. Derivation and manipulation of a generalised Erlang distribution

53. Royal Holloway lectures (Quantitative Methods in Economics II)

54. Quick memo on five basic types of first-order differential equation

55. Integrating integer powers of a sine function via a hypergeometric function

56. Electronics (Password Protected Page)

57. Surface charge density of a conducting disk from that of a conducting ellipsoid

58. Useful formula for integrating integer powers of a sine function over a period

59. Equivalent integral formulae for Bessel functions of the first kind, order zero

60. A note on a Fourier sine series solution to a heat flow problem

61. Legendre-transforming a Lagrangian mechanics problem into a Hamiltonian one

62. Overview of mathematical modelling ideas in single particle quantum mechanics

63. A note on Singular Value Decomposition and Principal Components

64. Boolean array indexing and finding multiple zeros of a function at once

65. Fast Fourier Transform by hand

66. Quadratic B-Spline interpolation of points on a modulus function

67. A note on an unusual system of two masses connected by a spring

68. Using wxdrawdf in MAXIMA to plot a phase portrait with a stable limit cycle

69. Canonical derivation of the mean and variance of the binomial distribution

70. From simple random walk to Wiener process and diffusion equation

71. Ornstein-Uhlenbeck process: derivation and simulation of its pdf and moments

72. Fourier transform of a function that is scaled and translated in either order

73. Zero-field singularity of magnetic susceptibility in a 4-D Ising model

74. Boltzmann distribution, Gibbs-Shannon entropy and Helmholtz free energy

75. Using the Python library NetworkX to find all Hamiltonian cycles in a graph

76. A max-flow/min-cut network problem solved both manually and with Python

77. Using Prüfer sequences to count and classify irreducible labelled 10-node trees

78. Why we can omit the modulus symbol in ln(|x|) in the integrating factor method