Dr. Christian Reisswig

Computational Astrophysics & Numerical Relativity

Author Archive

Multiblocks in general-relativity with flux-conservative AMR


I and collaborators have successfully implemented and tested a multiblock scheme with flux-conservative adaptive mesh refinement (AMR). Multiblocks allow one to cover the simulation domain with multiple curvi-linear grid patches. This enables a greater flexibility in adapting the grid resolution to the problem symmetry. For instance, the gravitational-wave zone or the outer layers of a star exhibit… Read More

A new high-order nullcone evolution scheme

I and collaborators have developed a new high-order algorithm for solving the characteristic initial boundary value problem of the Einstein equations. In the characteristic initial boundary value problem of general relativity, the Einstein equations are recast using a particular coordinate system along outgoing nullrays (along the light (or null) cone). The characteristic Einstein evolution system… Read More

Cauchy-characteristic extraction in numerical relativity


I and collaborators have developed and applied the gravitational-wave extraction technique of Cauchy-characteristic extraction (CCE) to simulations of binary black hole mergers, stellar collapse, and binary neutron star mergers to compute the first unambiguous and gauge-invariant GW signal ever extracted for these problems, allowing me to measure, for the first time, the non-linear memory effect in… Read More