Fibonacci Fast Convergence for Neutrino Oscillations in Matter

Understand

Understanding neutrino oscillations in matter requires a non-trivial diagonalization of the Hamiltonian.

• As the exact solution is very complicated, many approximation schemes have been pursued.
• Here we show that one scheme, systematically applying rotations to change to a better basis, converges exponentially fast wherein the rate of convergence follows the Fibonacci sequence.
• We find that the convergence rate of this procedure depends very sensitively on the initial choices of the rotations as well as the mechanism of selecting the pivots.