Sebastian Murk

Senior Postdoctoral Research Fellow @CharlesUniPRG \\ Gravitational Physics and Quantum Information Theory \\

[Sebastian Murk @sebmurk]

Selected as an Editor's Pick by the International Journal of Modern Physics D (@worldscientific ): "Nomen non est omen: Why it is too soon to identify ultra-compact objects as black holes"

DOI: https://t.co/PI6HPzQ7ei
arXiv: https://t.co/FvDGc35LCk

[arXiv bot (quant-ph) @krxiv_quant_ph]

Connecting Quantum Tomography and Quantum Retrodiction
https://t.co/0XpNYUPvzA
Sebastian Murk, Ian Tan, Fabian Müller, Dominik Šafránek.
https://t.co/MoINtrNQKd

[General Relativity and Quantum Cosmology Papers @RelativityPaper]

Covariant variation for point-particle Lagrangians

Finnian Gray, Sebastian Murk, Daniel R. Terno
https://t.co/pqhVkJooDt [𝚐𝚛-𝚚𝚌]

[Quantum Physics Papers @QuantumPapers]

Connecting Quantum Tomography and Quantum Retrodiction

Sebastian Murk, Ian Tan, Fabian Müller, Dominik Šafránek
https://t.co/Nilk4BVW9b [𝚚𝚞𝚊𝚗𝚝-𝚙𝚑 𝚖𝚊𝚝𝚑-𝚙𝚑 𝚖𝚊𝚝𝚑.𝚂𝚃 𝚙𝚑𝚢𝚜𝚒𝚌𝚜.𝚍𝚊𝚝𝚊-𝚊𝚗]

[Sebastian Murk @sebmurk]

yields a simple local Lagrangian whose helicity term reproduces the post-eikonal, polarization-dependent acceleration.

#GeneralRelativity #TheoreticalPhysics

[Sebastian Murk @sebmurk]

🚨New preprint📑
https://t.co/ScjdZ3AwIy

Point-particle Lagrangians in general relativity appear in many different settings such as spinless test particles, massive spinning bodies, and high-frequency polarized light rays beyond geometric optics. In each case the dynamics ...

[Sebastian Murk @sebmurk]

an action principle to equations of motion and conserved quantities. For massive spinning bodies, our formalism streamlines the derivation of the Mathisson–Papapetrou–Dixon (MPD) equations. For polarized light, it ...

[Sebastian Murk @sebmurk]

The generalized problem keeps the same inference objective, but the gradient is generally not determined by the Petz recovery formula.

[Sebastian Murk @sebmurk]

Quantum tomography and quantum retrodiction both ask which input state best explains an observed output, but they are usually approached with different mathematical tools: maximum-likelihood estimation in tomography vs. recovery maps in retrodiction.

https://t.co/ezQVR9Av2z

[Sebastian Murk @sebmurk]

... the noncommutative generalization for arbitrary quantum channels is based on the inverse Kubo-Mori action. A key takeaway is that maximum-likelihood tomography can be interpreted as retrodiction through a measurement channel.

[Sebastian Murk @sebmurk]

Tomorrow, Friday 12 June 2026, at 11:45 CEST, I’ll present our paper “Classical-quantum gravity as quantum gravity in disguise” at the RQI Postdoc Meeting.

Preprint: https://t.co/fCg6tkNZSm
Livestream/recording: https://t.co/bQIHx8Y2Ox

#QuantumGravity #RQI

[Sebastian Murk @sebmurk]

New paper in JHEP🎓
https://t.co/8nmMO4vGgR

[Sebastian Murk @sebmurk]

Our paper “Classical-quantum systems breaking conservation laws” (https://t.co/fCg6tkOxHU) was recently featured in Dr. Blitz's peer review series: https://t.co/drHcDiyWqW

Thank you for the comprehensive walkthrough!

[Masahiro Hotta @hottaqu]

豪州マッコーリ大のテルノさんとOISTのマークさんとの共同研究です。物質を量子とし、時空を古典とするモデルでは、回転対称性をもつダイナミクスでも角運動量は保存しないという指摘です。時空だけ古典のままにする場合、ネーターの定理は成り立たないという話になります。
https://t.co/Zr1G8oKeRe

[Sebastian Murk @sebmurk]

I could be wrong, but to the best of my knowledge we present the first explicitly constructed example of a fully closed classical-quantum hybrid system in which total angular momentum is not conserved despite the underlying equation of motion being rotationally invariant.

[Sebastian Murk @sebmurk]

Excited to share this new preprint in collaboration with Masahiro Hotta and Daniel Terno🎓

https://t.co/fCg6tkOxHU

[Sebastian Murk @sebmurk]

New paper with Robie Hennigar (@durham_uni), David Kubizňák (@CharlesUniPRG), and Ioannis Soranidis (@Macquarie_Uni)‼️

A truly international collaboration: four countries, three continents, and a shared fascination with black hole thermodynamics.

https://t.co/91eVn5saIt