Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
After an incredible few years, my time at the AEI has come to an end. I’m grateful for the lovely memories and collaborators I’ve had the privilege to work with.
I’m excited to start a new chapter as a Marie Sklodowska-Curie Postdoctoral Fellow at the University of Southampton.
“This is a story of curiosity: our drive to understand where we come from, how the universe works, and what fundamental forces shape our reality.” m.independent.ie/irish-news/i...
I’m incredibly proud to be part of this and to have my simulations turn into the first publicly available scattering and dynamical capture waveforms!
Below is a plot I made for the Einstein Toolkit Blue Book (arXiv:2503.12263) showing the waveforms SXS:BBH:3999 (scatter) and SXS:BBH:4000 (capture).
Benjamin Leather, Alessandra Buonanno, Maarten van de Meent
Inspiral-merger-ringdown waveforms with gravitational self-force results within the effective-one-body formalism
https://arxiv.org/abs/2505.11242
A light blue diagram depicting the sea, with the water's surface at the top, and just below it is an outline of the Mary Rose, with the depth (12m, 40ft or 6.7 fathoms). There is a line showing the seabed, which takes a rapid dive into the vertical...
On the anniversary of the sinking of the Titanic, we thought we'd answer a question that's often asked,
"If they raised the Mary Rose, why not raise the Titanic?"
Allow our scaled diagram to explain...
Welcome to the #LECSTalks! series, where we showcase the people, activity, and science taking place around the LISA Early Career Scientists community. 🎤
Today we feature Ben Leather, postdoctoral researcher at the MPI for Grav Physics, talking about Waveform Modelling with Gravitational Self-Force.
Kevin De Bruyne is the greatest midfielder in premier league history. By a distance. City’s greatest ever player. We were privileged to witness his era. Not sure we’ll ever see someone with that talent again.
A screenshot of the paper, "Quadratic Quasinormal Mode Dependence on Linear Mode Parity", in Physical Review Letters.
Our recent work on Quadratic Quasinormal Mode Dependence on Linear Mode Parity has now been published in Physical Review Letters!
journals.aps.org/prl/pdf/10.1...
🧪🔭⚛️
A new major update to the Teukolsky package has been released (version 1.1.0). A major new feature the the ability to PN expand various Teukolsky radial functions (contribution from Jakob Neef)
Photograph at the stage of Dr. Strangelove in the Bord Gais Theatre in Dublin.
I had the pleasure of experiencing @aiannucci.bsky.social’s brilliant stage adaptation of Dr. Strangelove last night.
Steve Coogan and the entire cast were outstanding, and the entire cast brought this masterpiece to the stage in incredible fashion.
One of the best things I’ve seen in years.
Edwin Hubble seated at Mt. Wilson Observatory’s 100” Hooker telescope. He is sitting in a wooden chair, looking through an eyepiece. Hubble’s hand rests on a small wheel that he might turn to adjust his view. He is wearing a gray or light colored suit.
Edwin Hubble submitted his paper "A relation between distance and radial velocity among extra-galactic nebulae" #OTD in 1929.
It showed that "extra-galactic nebulae" were moving away from us with a velocity that increased linearly with distance. 🧪 🔭 ⚛️
Image: Carnegie Observatories
Please, I beg of you, let this end up in court.
London pricing reaches new low.
Our 1999 tribute kit was meant for us to to **look** like when we were in League One, not play like when we were there as well.
Artist’s impression of the horizons and curvature of a binary black hole system. Generated using Paraview.
(1/7) As I’m new here I thought I should introduce myself!
My name is Olly Long and I am a researcher working on modelling the binary black hole problem in General Relativity.
A doodle with a conformal diagram, with a Cauchy surface, world lines of merging black holes, a schematic bar detector and interferometer, with labels: Sources; approximation methods; Numerical Relativity; Cauchy problem; Null Infinity. There is also a little fellow in a bowler hat at the bottom left, looking perplexed at the conformal diagram.
"The patchwork of gravitational radiation research"
Doodle opposite the introduction of the Proceedings of the 1982 Les Houches lectures, Eds. Nathalie Deruelle and Tsvi Piran. Apparently the art is due partly to Nathalie and partly to Philippe Tourrenc.
🧪⚛️🔭🧮
Benjamin Leather
Gravitational self-force with hyperboloidal slicing and spectral methods
https://arxiv.org/abs/2411.14976
A Penrose diagram showing hyperboloidal foliation, but with a mint green colour.
Now with added mint green hyperboloidal foliation.
Penrose diagram for the Schwarzschild exterior spacetime region with minimal gauge hyperboloidal slices. The solid blue curves depict hyperboloidal time surfaces τ−constant extending between the black-hole horizon H+ at σ = 1 and future null infinity I+ as σ = 0.
6/ Next Steps
A similar Lorenz gauge metric reconstruction technique can now be implemented in Kerr. This, combined with the methods of this paper framework, paves the way for extending second-order GSF calculations to Kerr. I shall leave with you my nice Penrose diagram from the paper!
A comparison of the Newtonian-normalised Detweiler redshift with the 21.5PN expression from Kavanagh et al. The redshift is plotted as a function of the gauge invariant radius, x = (MΩφ)2/3, hence the rightmost boundary of the plot is towards the central black hole horizon. We have labelled the innermost stable circular orbit (ISCO) at x = 1/6 to help illustrate this. Our (Newtonian-normalised) redshift data is shown by the top (blue) dots and the full 21.5PN expression is plotted as the solid (blue) curve. We subtract successive PN terms from the leading-order normalised redshift and compare these residuals to the residuals of the successive PN series.
![A plot of the nonzero (conformal) BLS modes for ℓ=2 and m=2 throughout the spacetime that extends from the null-infinity (σ=0) to the horizon (σ=1). In this orbital configuration, the particle is located at σp=0.2. The field in Domain1, {D1}=[0,σp], is shown by the red curves, while the fields in Domain 2, {D2}=[σp,1], are shown by the blue curves.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:ctferuogbjc5psbjfmnpyr3c/bafkreidgu65qyiuiorwev5b2kvxbluw6anehbkzaxvz4mbywbcyozau5qe)
A plot of the nonzero (conformal) BLS modes for ℓ=2 and m=2 throughout the spacetime that extends from the null-infinity (σ=0) to the horizon (σ=1). In this orbital configuration, the particle is located at σp=0.2. The field in Domain1, {D1}=[0,σp], is shown by the red curves, while the fields in Domain 2, {D2}=[σp,1], are shown by the blue curves.
5/ Key Results
I reconstruct Lorenz gauge metric perturbations by gauge-transforming from the Regge-Wheeler gauge. This method calculates metric perturbations throughout the spacetime efficiently. It also enables accurate computations of fluxes, the Detweiler redshift, and self-force corrections.
A plot of the ℓ-mode contribution to the radial self-force, Fr,ℓ for the differing degrees of regularisation for a secondary on an orbit of rp/M=10. We show the results for the unregularised (red squares) and the mode-sum-regularised (blue triangles) radial self-force.
4/ Why Lorenz Gauge?
The Lorenz gauge simplifies the regularisation of singularities in GSF by ensuring isotropic singular behaviour. It also avoids divergences at null infinity and the horizon. Critically, this gauge aligns with the current second-order GSF framework.
A plot of the conformal spin-0 Regge-Wheeler field through the compactified spacetime. An inset shows the decay of the spectral convergence of the Chebyshev coefficients of the solutions within each domain.
A plot of the conformal gauge field through the compactified spacetime. An inset shows the decay of the spectral convergence of the Chebyshev coefficients of the solutions within each domain.
3/ Novel Approach
I extend hyperboloidal slicing and spectral methods from a scalar toy model to full gravitational perturbations in the Lorenz gauge. These methods allow for compactified domain calculations that efficiently span the entire spacetime.
2/ How This Work Connects to EMRIs
Accurate GSF calculations require solving Einstein’s field equations for the smaller body’s perturbation of the spacetime. This work introduces a novel approach to calculating such a metric perturbation.
An artist's impression showing an evolution of a complicated extreme-mass-ratio inspiral around a Kerr black hole.
1/ EMRIs and GSF
Extreme-mass-ratio inspirals (EMRIs) are key targets for future GW observatories like LISA. Their tiny mass ratios mean small corrections accumulate over thousands of orbits, making precise modelling essential. GSF theory is central to capturing these effects for accurate waveforms.
A screenshot of the title, author and abstract from the arXiv preprint of the paper.
🎉 It's new paper day! 🎉
I'm thrilled to share my new paper: "Gravitational self-force with hyperboloidal slicing and spectral methods."
arxiv.org/pdf/2411.14976
So, what is this all about? 🧵 /6
🧪🔭⚛️ #🧮
New paper the cites the BHPToolkit: "Gravitational self-force with hyperboloidal slicing and spectral methods" by Benjamin Leather, arxiv.org/abs/2411.14976
We live in hyperbolic times. So here's a paper about hyperbolic times, fresh off the press, published just yesterday.
https://buff.ly/3OjsJi3
Resharing this gravitational waves starter pack because I've added more people now. If there's anyone still missing from it, please let me know.
go.bsky.app/HrAJX35