432 citations · 1.6k across the 26 of their papers we have counts for
26 papers
Matrix completion and semidefinite matrices
Olaf Dreyer
Positive semidefinite Hermitian matrices that are not fully specified can be completed provided their underlying graph is chordal. If the matrix is positive definite the completion…
Completing correlation matrices
Olaf Dreyer, Horst Köhler, Thomas Streuer
We describe a way to complete a correlation matrix that is not fully specified. Such matrices often arise in financial applications when the number of stochastic variables becomes…
Beyond information: A bit of meaning
Olaf Dreyer
Is our world just information? We argue that our current notion of information has one serious shortcoming: It is quite literally meaningless. We suggest a meaningful extension of…
The world is discrete
Olaf Dreyer
We argue that the scale-free spectrum that is observed in the cosmic microwave background is the result of a phase transition in the early universe. The observed tilt of the spectr…
Entropy from near-horizon geometries of Killing horizons
Olaf Dreyer, Amit Ghosh, Avirup Ghosh
We derive black hole entropy based on the near-horizon symmetries of black hole space-times. To derive these symmetries we make use of an -plane close to a Killing horizon.…
From bricks to quasinormal modes: A new perspective on black hole entropy
Michele Arzano, Stefano Bianco, Olaf Dreyer
Calculations of black hole entropy based on the counting of modes of a quantum field propagating in a Schwarzschild background need to be regularized in the vicinity of the horizon…