We would like to invite you to our Fundamentals of the Universe mini-symposium, which will take place online and at the Van Swinderen Huys on Friday, 24 September 2021 at 9 AM. To receive an invitation please register to the event via this __online form__!

The following poster will be presented during the poster session at 12:00-14:00:

__Jann Aschersleben__

**Title: **Energy reconstruction using pattern spectra and machine learning for the Cherenkov Telescope Array

**Abstract: **The Cherenkov Telescope Array (CTA) will be the major global instrument for very-high-energy astronomy over the next decade. Each telescope will provide a snapshot of gamma-ray induced particle showers by capturing the induced Cherenkov emission at ground level. The simulation of such events provides images that can be used as training data for convolutional neural networks (CNNs) to determine the energy of the initial gamma rays. Compared to other state-of-the-art algorithms, analyses based on CNNs promise to further enhance the performance to be achieved by CTA.
Pattern spectra are commonly used tools for image classification and provide the distributions of the shapes and sizes of various objects comprising an image. In this work, we generate pattern spectra from simulated gamma-ray events instead of using the raw images themselves in order to train our CNN for energy reconstruction. Thereby, we aim to obtain a significantly faster and less computationally intensive algorithm, with minimal loss of performance.

__Martine Schut__

**Title: **3-qubit Quantum Gravity Induced Entanglement of Masses

**Abstract:** Recent publications about testing the nature of gravity propose a table-top experiments that use the detection of entanglement to witness quantum gravity. Using two spatial superpositions, their mutual gravitational interaction can entangle the two test masses. Measuring this entanglement could prove the quantum nature of gravity. These measurements become more difficult once interaction with the environment is taken into account. Due to these interactions the system decoheres. In order to make the experiment more robust against decoherence effects, we propose a setup with 3 spatial superpositions: the 3QGEM experiment.

__Jorge Becerra__

**Title: **A Hopf approach to the universal tangle invariant

**Abstract:** Classically (framed) tangles are viewed in a vertical position as knotted ribbons in a cylinder. However this realisation is not very useful if one wants to study natural operations on tangles as merging or cutting along. We introduce a suitable notion of tangles that fits our purpose and generalises the classical tangles. Further we show how the universal tangle invariant coming from a (ribbon) Hopf algebra can be seen as a monoidal natural transformation.

__Giovanni van Marion__

**Title: **Applying Transition State Theory to Sphaleron Transitions

**Abstract:** Sphaleron transitions are expected to occur in certain gauge theories. In the electroweak sector, for instance, they can theoretically produce or wash out a matter anti-matter asymmetry and are thus of interest when investigating the baryon asymmetry problem$^1$. In physics, these transitions are usually investigated by path integral techniques, but ultimately they share great conceptual similarity with reaction rate problems in quantum mechanics, like those found in theoretical chemistry. In chemistry, these rates are computed using transition state theory. In our research we aim to apply a variant, normal form transition state theory, to reproduce and improve the path integral results (numerically). This poster presents a conceptual explanation of sphalerons and their rates and talks about the toy model to which we apply these techniques.

__Kevin van Helden__

**Title: **Classification of semistrict Lie 2-algebras

**Abstract:** In classical mechanics, the dynamics of a system are governed by a Lie algebra. If we replace the point particles from that theory by classical strings, the new mathematical structure governing the dynamics is a Lie 2-algebra. We will see how structure emerges, an example, why it is important to classify them and, last but not least, what their classification looks like.

__Wout Moltmaker__

**Title: **Quantum Invariants of Biframed Knotoids

__Boudewijn Bosch__

**Title: **The Witten–Reshetikhin–Turaev Invariant and its Connection to Quantum Modular Forms

__X. Chen__

**Title:** NEXT Step Towards Neutron-Rich Heavy Nuclides

__Thomas Floss__

**Title:** Unraveling the Start

__Eric Pap__

**Title:** Exceptional Points in Adiabatic Quantum Mechanics

**Abstract: ** In adiabatic quantum mechanics, the phenomenon of Berry/geometric phase is well-known for Hermitian Hamiltonians. The phase corresponds to parallel transport on a bundle of eigenstates. However, this standard theory does not apply to non-Hermitian Hamiltonians, which govern open quantum systems. The problem comes from non-cyclic states: states that return with a different energy, even though all system parameters are restored to their original values. These exchanges of energies and states occur around specific degeneracies, known as exceptional points. We describe a framework that generalizes the standard theory to include these non-cyclic states.

__Bohdan Bidenko__

**Title:** Tension between early and late universe expansion measurements

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