The Electromagnetic Christodoulou Memory Effect and its Application to Neutron Star Binary Mergers

Abstract

Gravitational waves are predicted by the general theory of relativity. It has been shown that gravitational waves have a nonlinear memory, displacing test masses permanently. This is called the Christodoulou memory. We proved that the electromagnetic field contributes at highest order to the nonlinear memory effect of gravitational waves, enlarging the permanent displacement of test masses. In experiments like LISA or LIGO which measure distances of test masses, the Christodoulou memory will manifest itself as a permanent displacement of these objects. It has been suggested to detect the Christodoulou memory effect using radio telescopes investigating small changes in pulsar's pulse arrival times. The latter experiments are based on present-day technology and measure changes in frequency. In the present paper, we study the electromagnetic Christodoulou memory effect and compute it for binary neutron star mergers. These are typical sources of gravitational radiation. During these processes, not only mass and momenta are radiated away in form of gravitational waves, but also very strong magnetic fields are produced and radiated away. Moreover, a large portion of the energy is carried away by neutrinos. We give constraints on the conditions, where the energy transported by electromagnetic radiation is of similar or slightly higher order than the energy radiated in gravitational waves or in form of neutrinos. We find that for coalescing neutron stars, large magnetic fields magnify the Christodoulou memory as long as the gaseous environment is sufficiently rarefied. Thus the observed effect on test masses of a laser interferometer gravitational wave detector will be enlarged by the contribution of the electromagnetic field. Therefore, the present results are important for the planned experiments.

23 pages, 2 figures

References in corpus (10)

• The missing link: Merging neutron stars naturally produce jet-like structures and can power short Gamma-Ray Bursts
• Producing ultra-strong magnetic fields in neutron star mergers
• Neutrino signatures and the neutrino-driven wind in Binary Neutron Star Mergers
• Magnetized Neutron Star Mergers and Gravitational Wave Signals
• Accurate evolutions of inspiralling and magnetized neutron-stars: equal-mass binaries
• General relativistic simulations of magnetized binary neutron star mergers
• Observable Signatures of a Black Hole Ejected by Gravitational Radiation Recoil in a Galaxy Merger
• Can magnetic fields be detected during the inspiral of binary neutron stars?
• Eccentric Black Hole-Neutron Star Mergers
• Levy model for interstellar scintillations

Cited by in corpus (25)

• New Gravitational Memories
• An electromagnetic analog of gravitational wave memory
• A perturbative and gauge invariant treatment of gravitational wave memory
• Examination of a simple example of gravitational wave memory
• Global aspects of radiation memory
• Gravitational wave memory in $\Lambda$CDM cosmology
• Gravitational wave memory in de Sitter spacetime
• Testing Gravitational Memory Generation with Compact Binary Mergers
• Soft Charges and Electric-Magnetic Duality
• The sky pattern of the linearized gravitational memory effect
• Berry Phases on Virasoro Orbits
• Implications of Superrotations
• Gravitational Memory and Compact Extra Dimensions
• Gravitational Wave Displacement and Velocity Memory Effects
• Memory Effect in Anti-de Sitter Spacetime
• New Effects in Gravitational Waves and Memory
• Kerr Black Holes and Nonlinear Radiation Memory
• Answering the Parity Question for Gravitational Wave Memory
• Electromagnetic Memory Effect Induced by Axion Dark Matter
• Electromagnetic memory in arbitrary curved space-times
• Comment on "Boosted Kerr black holes in general relativity"
• Resolving a gravitational wave memory paradox
• Weyl Cosserat Elasticity and Gravitational Memory: An Effective Microstructured Model of Spacetime
• The Gravitational Wave Memory from Binary Neutron Star Mergers
• Gravitational waves decohere quantum superpositions