Recent Physics Research Paper

title:
The Perspectives of Non-Ideal Quantum Reference Frames

collaborators:
Ladina Hausmann, institute of theoretical physics, ETH Zürich, Switzerland
Dr. Esteban Castro-Ruiz, institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Austria

abstract
We define the perspective of any quantum reference frame (QRF) and construct reversible transformations between different perspectives. Our construction is based on two principles motivated operationally by the change from relative to absolute coordinates and leads to an incoherent group averaging approach with general symmetry group. Thereby, it extends the framework of [arXiv:2110.13199] from ideal QRFs, which generally require infinite resources like energy or angular momentum, to non-ideal QRFs, with only finite resources. We find that the perspective of a non-ideal QRF deviates significantly from that of an ideal QRF: Firstly, systems described relative to a non-ideal QRF appear superselected. Secondly, the structure of the perspective of a non-ideal QRF attests that successive relational operations on a system lead to back-reaction on this QRF.

pre-print:
doi:10.48550/arXiv.2512.19343

PDF file (v2):
paper

Astrophotography

In my spare time I take images of the moon, stars, galaxies and other night sky objects with my Celestron telescope and either a Nikon DSLR camera or a ZWO ASI astro camera. You can find more details and all my images here. Below is an overview of my best images as well as my latest image.

My astrophotography images are protected under the CC BY-NC-SA 4.0 license:

IC 5146 - Cocoon Nebula

The cocoon nebula is a reflection and emission nebula. Thus, it reflects light, but also emits its own. Photographed with the help of Anna Bickel.

M27 - Dumbbell Nebula

The Dumbbell nebula is a planetary nebula (which has nothing to do with planets) in the constellation Vulpecula. M27 is the cast-off outer layers of a dead star, whose core is still visible as a white dwarf in the centre of the nebula. This is already my fifth and currently best rendering of the Dumbbell nebula; photographed with help from Anna Bickel.