Erlangen Centre for Astroparticle Physics

ECAP Seminar: Foteini Oikonomou
2025-02-06 13:00 - 14:00 (Europe/Berlin) | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Ultra-high energy cosmic rays: Constraints on the maximum-energy distribution of the sources and the possible role of ultra-fast outflows in active galactic nuclei
An open question in the search for ultra-high-energy cosmic-ray (UHECR) sources is whether they are few and prominent or if a large population of sources collectively contributes to the diffuse flux. Motivated by this question, we investigated whether the latest UHECR data are consistent with originating from a population of sources that exhibit substantial diversity in terms of the cosmic-ray spectra they produce. We found that the fit to the cosmic ray data requires sources that are intrinsically very similar in terms of the maximum energy reached. This is surprising, considering the sizeable astrophysical diversity exhibited by the candidate astrophysical source populations. One source class that may satisfy the constraints imposed by the UHECR observations is non-jetted active galactic nuclei. An increasing number of observations suggest that semi-relativistic winds, termed ultra-fast outflows, are present in a large fraction of these sources. In this talk, I will show that cosmic ray nuclei can be accelerated to ultra-high energies in such ultra-fast outflows. Ultra-fast outflows can, therefore, possibly account for a substantial fraction of the observed diffuse UHECR flux.

ECAP Seminar: Oliver Friedrich, LMU Sternwarte
2025-05-08 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Forcing neutrinos to obey the holographic principle
Gravity does not like the vast amounts of states present in QFT, and
quantum gravitational effects are expected to drastically reduce the
dimension of the QFT Hilbert space. This is e.g. achieved by “operator
dressing”, which changes the commutation relations of quantum fields.
In https://arxiv.org/abs/2402.11016 we build a model for neutrinos,
that incorporates this dressing and fixes it such that neutrinos obey
a cosmic entropy bound. A key consequence of this construction is that
particles scatter in the vacuum. This e.g. implies a finite mean free
path of cosmic neutrinos. We confront this result with observed
neutrino emissions and find that the holographic principle is
potentially in tension with current neutrino data.

ECAP Seminar: Philipp Windischhofer, U Chicago
2025-05-22 13:00 - 14:00 | Physikum, Hörsaal HF, Staudtstr. 5, Erlangen, 91058, Germany
Exploring the Universe at the Highest Energies: when Particle Physics and Astronomy meet
High-energy neutrinos propagating over cosmological distances are the ideal messenger particles for astrophysical phenomena, but the neutrino landscape above 10 PeV is still mostly unexplored. At these extreme energies, neutrinos can image the most extreme objects in remote corners of our cosmos and help access fundamental physics at extremely short distances.In this talk, I will show how we are presently constructing the Radio Neutrino Observatory in Greenland, the largest-ever terrestrial neutrino detector, and how the century-old physics of electrodynamics plays a central role in its operation. Combining ideas from particle collider instrumentation with high-performance computing, we will see what it takes to fully exploit the science potential of this unique instrument and thereby extend neutrino astronomy into the regime of the exaelectronvolt.

ECAP Seminar: Benedikt Bergmann, IEAP/CTU, Prague
2025-06-05 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Particle tracking and identification with Timepix-series detector setups in nuclear, particle and astrophysics
In high energy physics experiments, hybrid pixel detectors are an integral part of the tracking systems closest to the interaction points, where their good spatial resolution and high radiation resilience allow for particle tracking by connection of “dots” registered in different layers of an onion-like detector. Another approach to particle detection and tracking relies on a complex analysis of the imprints seen in the pixel matrices (tracks), which provide a rich set of features. These allow for identification of impinging particles, particle trajectory or reaction kinematics reconstruction. The latter is particularly valuable for applications with limited resources, for example in space experiments, but it also enables fundamental-science-reach measurements with simple table-top experiments. In this contribution, I will present the latest results from Timepix-type detectors used within LHC experiments, as space radiation monitors in low Earth orbit, their possible application for measurement for galactic-cosmic-ray properties or as an X-ray polarimeter.

ECAP Seminar: Branden Allen, University of Hawaii
2025-06-12 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Introduction to the Space Science and Engineering Initiative, and Opportunities and Applications for the Next Generation of X and gamma-ray Detector Systems and Technologies
The Space Science and Engineering Initiative (SSEI) was created as a joint effort between the UHM College of Engineering (CoE) and the Institute for Astronomy (IfA) for the establishment of an interisland advanced technology research and development center based in Hilo, which aims to significantly expand technical capabilities to support the space sciences, particularly targeting application for the observatories on Maunakea and Haleakalā. Here, I will discuss the current status of the SSEI and give a brief overview of our current portfolio of activities.
Afterward, I will discuss my own research program which focuses primarily on the development of high-energy detectors, associated technologies, telescopes and missions for spaceflight. This will be followed by a discussion of plans and potential for their future deployment for use in astrophysics and planetary science.

ECAP Seminar: Mauricio Bustamante
2025-06-26 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Fundamental physics with high-energy and ultra-high-energy cosmic neutrinos
High-energy cosmic neutrinos probe fundamental physics at scales of energy and distance otherwise unreachable, where new physics may manifest. Since the discovery of TeV-PeV astrophysical neutrinos in 2013, we have explored this progressively more broadly and with increasing precision, thanks to a growing number of detected neutrinos and to improvements in reconstruction and analysis techniques. By means of illustration, I will survey the rich landscape of high-energy physics with cosmic neutrinos, from the perspectives of theory and experiment. I will also touch upon new opportunities made possible by the recent discovery of an ultra-high-energy neutrino, with about 200 PeV, by KM3NeT—with a warning. Looking ahead, I will show two prospects for transformative change in the next decade, driven by new, upcoming neutrino telescopes: a boost in the detection rate of TeV-PeV neutrinos and the possible detection of more ultra-high-energy neutrinos.

ECAP Seminar: Kendall Mahn, Michigan State University
2025-10-13 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
You’re sending particles across a country? The Tokai to Kamioka experiment
Neutrinos are a tiny subatomic particle with surprising properties under active study. In particular, neutrinos oscillate, that is, they convert from one type of neutrino to another, is a surprising phenomenon under active study. The origin of neutrino mass is important for astrophysics, cosmology and particle physics, and many open questions surrounding neutrino oscillation exist. The Tokai-to-Kamioka (T2K) neutrino oscillation experiment sends a beam of muon flavor neutrinos or antineutrinos 295km across Japan. This seminar will talk about the wonderful world of neutrinos, the surprising landscape of neutrino oscillation, through the lens of recent activities on T2K, and toward the future, global neutrino exploration of neutrinos.

ECAP Seminar: Milena Crnogorcevic, Stockholm University
2025-10-23 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Gamma Rays from the Littlest Galaxies: Tracing Accretion and Dark Matter in the Low-Mass Universe
Now in its 17th year of operation, the Fermi Large Area Telescope (LAT) continues to transform our understanding of the smallest galaxies in the Universe. Dwarf galaxies host some of the most extreme environments known—from ultra-faint systems dominated by dark matter to those harboring actively accreting intermediate-mass black holes (IMBHs). In the first part of this talk, I will present results from the first systematic Fermi-LAT search for gamma-ray emission from active galactic nuclei in dwarf galaxies, revealing hints of a soft-spectrum excess that may trace the onset of high-energy activity in low-mass black holes. In the second part, I will discuss our complementary search for dark matter annihilation in dwarf galaxies, including limits from ultra-faint systems. Together, these studies illustrate how the littlest galaxies provide powerful and complementary laboratories in gamma rays—probing both the physics of black hole growth and the nature of dark matter. Looking ahead, I will address the (exciting) uncertainties and challenges facing space-based gamma-ray astronomy, as well as highlight the promising prospects offered by next-generation ground-based gamma-ray observatories.

ECAP Seminar: Lucas de Sa, Heidelberg University
2025-11-20 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Prospects for pulsars and pulsar associations in multi-messenger astrophysics with population synthesis
Population synthesis seeks to integrate the full framework of stellar evolution with predictions for observations of different products of said evolution, potentially allowing constraints to be placed on multiple evolutionary steps at the same time. It has become a central tool in gravitational-wave astronomy when simulating populations of compact object mergers and predicting merger rates over redshift, where it nevertheless faces the challenge of dealing with the high level of uncertainty surrounding massive stellar evolution, and the degeneracy between multiple physical assumptions when making predictions for a single kind of event. This degeneracy, however, could be lifted in part by accounting for a broader range of stages a star goes through during its life, as well as alternative outcomes. In this talk, I will explore the prospects of using these same tools to study observed populations of pulsars and pulsar associations – pulsar wind nebulae and halos. In particular, I will highlight current advances in supernova theory and stellar angular momentum evolution, and the potential for a more detailed picture of pulsar formation. I will also present ongoing work on the generation of synthetic pulsar association populations for the study of observations of current gamma-ray observatories, in particular HAWC, and for the prediction of observations by the future SWGO.
