Institut für Theoretische Physik, Physikalisches Institut, Goldene Box
Hydrodynamic attractors describe how strongly interacting systems behave like fluids even far from equilibrium, a phenomenon first seen in heavy-ion collisions. We investigate whether this can be observed in real time using ultracold atomic gases. Despite being dilute, these gases display remarkable fluid-like behavior, including nearly perfect fluidity. Through microscopic calculations, we show how they relax toward equilibrium and find that analytical attractor solutions capture the early-time dynamics well, before standard hydrodynamics kicks in.
Tuesday, 19 May 2026
16:30
Heidelberg Joint Astronomical Colloquium
Oscar Agertz
Early Galactic Disks and Their Connections to Present-Day Galaxies
Recent JWST and ALMA observations have revealed that a substantial fraction of galaxies at very high redshift are rotationally supported disks. Many of these systems host kinematically cold, or Âsettled, gaseous disks, a finding that stands in tension with the expectations of many galaxy-formation models. In this seminar, I will present an overview of cosmological simulations of disk-galaxy formation. I will discuss the properties of gas-rich, high-redshift disks, their turbulent nature, and how these early phases of disk assembly connect to spectroscopic and astrometric observations of the Milky Way. Finally, I will show new results indicating that turbulent, early-Universe galaxies are more susceptible to global gravitational instabilities, such as bar formation, than previously thought. These results carry important implications for the rapid buildup of galactic bulges and the fueling of central black holes. To arrange a visit with the speaker during the visit, please contact their host: Eva Schinnerer
Wednesday, 20 May 2026
09:30
Seminar Dynamik und Struktur von Atomen und Molekülen
Dr. Alexander Magunia; Excited atoms&molecules in strong fields
Science Soup with Fierce FELs
Central Seminar Room, library building
11:15
Gentner Colloquium for Astroparticle Physics
Prof. Dr. Ernst Pernicka (Curt-Engelhorn-Zentrum Archäometrie gGmbH)
Analytical chemistry at the MPIK and beyond: A retrospective
Central seminar room, library building
Wolfgang Gentner is best known for his work in nuclear physics but he also made significant contributions in the application of physical methods in other fields of research, such as cosmochemistry and biophysics. His latest engagement was the application of scientific methods in general to research in cultural history, since then known as archaeometry. The chemistry group contributed to the latter fields and also to neutrino research with inorganic chemical analyses and a review of two decades of involvement will be presented.
The seed of archaeometry sprouted in two directions at the MPIK, namely physical dating methods and the investigation of the provenance of raw materials in ancient societies with substantial supportof the VolkswagenStiftung. Further growth became possible through outsourcing dating research to the Heidelberger Akademie der Wissenschaften and to a university chair at the TU Bergakademie Freiberg. Eventually both lines of research were reunited in Mannheim at the Curt-Engelhorn-Znetrum Archäometrie gGmbH including radiocarbon dating with accelerator mass spectrometry, which was already discussed at the MPIK as an option in the 1980s. The activities of this non-university research centre, which is associated with the University of Heidelberg will be described with examples of internationally renowned results.
15:00
Seminar Stored and Cooled Ions
Holger Kreckel, MPIK
H3+, the Universe and Everything
Hybrid seminar: central seminar room, library building + Zoom: Meeting-ID: 915 1204 2752 Passcode: 758933
16:30
Zentrum für Quantendynamik Kolloquium
Dr. Matteo Zaccanti
Ultracold lithium-chromium mixtures: From mass-asymmetric fermionic matter to paramagnetic molecules
Physikalisches Institut, INF 226, K 1-3
Ultracold lithium-chromium mixtures: From mass-asymmetric fermionic matter to paramagnetic molecules Dr. Matteo Zaccanti Physics Department, University of Florence Quantum mixtures of different atomic species represent compelling frameworks for a variety of fundamental studies and quantum-technological applications, ranging from the exploration of exotic few- and many-body phenomena to the realization of novel molecular species in the ultracold regime. Here, I will first provide a general overview of the activities of our lab, primarily based on a novel Fermi-Fermi mixture of 6Li alkali and 53Cr transition-metal atoms, and currently focusing onto two main research topics: realization of quantum gases of LiCr molecules, and investigation of strongly interacting fermionic matter in presence of a large mass asymmetry. I will then discuss in more detail a recent study of transport dynamics of a small sample of ultracold lithium atoms  acting as light impurity particles  released into a large, ideal gas of chromium  that plays the role of a bath of heavy, point-like scatterers. Under strong interspecies interactions, by lowering the temperature we unveil a crossover from normal diffusion to subdiffusion. Simultaneously, a localized fraction emerges in the lithium gas, displaying no discernible dynamics over hundreds of collision events. Our findings, incompatible with a conventional Fermi-liquid picture, are instead captured by a model of a matter wave propagating through a (quasi-)static disordered landscape of point-like scatterers. These results point to a key, enhanced role of quantum interference in heavylight atomic mixtures, which emerge as versatile platforms for exploring disorder-free localization phenomena solely driven by a large mass difference.
17:00
SFB1225 ISOQUANT
Prof. Dr. Richard Schmidt
Meet&Mingle@ISOQUANT: mentoring und networking meeting for FLINTA* students in Physics
Institut für Theoretische Physik, Physikalisches Institut, Seminarbox, 1. Floor
tba
Thursday, 21 May 2026
11:15
Teekolloquium
Livia Ludhova, on behalf of the JUNO Collaboration
First Measurement of Reactor Neutrino Oscillations with JUNO
Grosser Hoersaal/Big Lecture Hall (library)
Neutrino oscillations are a fundamental quantum phenomenon demonstrating that neutrinos have non-zero mass and that the Standard Model in its minimal form must be extended. Their precise measurement plays a central role in particle physics and astroparticle physics, providing unique insight into the properties of neutrinos and their role in the Universe.
The Jiangmen Underground Neutrino Observatory (JUNO) in China, after more than 15 years from concept to full realization, started taking data in August 2025. With its 20-kiloton liquid scintillator target, JUNO is the first multi-kiloton liquid scintillator detector and has been designed to combine its large size with unprecedented energy resolution. This unique combination enables the observation of the fine oscillation pattern of reactor antineutrinos and opens a new level of precision in neutrino oscillation measurements.
In this talk, I will present the first oscillation results obtained during the initial phase of data taking. With only 59 days of data, JUNO has already achieved a world-leading precision measurement of the solar oscillation parameters
sin^2 theta_{12} and Delta m^2_{21},
demonstrating the excellent performance of the detector.
I will discuss the detector, analysis strategy, and physics implications of these results.
Finally, I will outline JUNO's broader scientific program, spanning precision measurements of reactor neutrino oscillations and a wide range of topics in astroparticle physics.
These results establish the foundation for JUNO's future precision neutrino physics program.
ARI Institute Colloquium
Laura Scholz Diaz
The effect of cosmological environment on galaxy stellar populations up to z=1
ARI, Moenchhofstrasse 12-14, Seminarraum 1.OG
In the LambdaCDM model, the large-scale matter distribution of the Universe regulates the hierarchical assembly of dark matter halos. At the centers of these halos, intricate baryonic processes unfold (e.g., gas accretion, star formation, chemical enrichment, stellar and black hole feedback), giving rise to observed galaxies. Yet, how the effect of halo and large-scale environment propagates into the baryonic physics of galaxies remains far from being fully understood. Stellar populations properties measured from high-SNR rest-frame optical spectra are powerful observational tracers of the past evolution of galaxies, which can be used to unveil the role of the environment in driving their formation. Throughout this talk, I will assess the effect of different halo and large-scale environmental metrics on stellar population properties and star formation histories of galaxies from spectroscopic surveys up to z=1. Our results suggest that halo properties and the initial matter density field have a profound effect on the quenching and star formation histories of galaxies, leaving an imprint on observed stellar populations and scaling relations of galaxies up to z=1. However, further observational constrains are needed, given current limitations in estimating halo properties and characterizing the large-scale environment, specially beyond the local Universe. Recent and upcoming large spectroscopic surveys with large statistics and exquisite cosmic web characterizations are key to bring light into this matter. In this context, future dedicated wide-field spectroscopic facilities, such as the WST concept, could revolutionize our view of how the cosmological environment of galaxies drives their formation.
Friday, 22 May 2026
17:00
Physikalisches Kolloquium
Prof. Mordechai (Moti) Segev
Photonic Time-Crystals and Light-Matter Interactions Therein
KIP, INF 227, Hörsaal 1
Photonic Time-Crystals and Light-Matter Interactions Therein Prof. Mordechai (Moti) Segev Technion, Israel Institute of Technology Photonic Time Crystals (PTCs) are dielectric media whose refractive index is strongly modulated periodically in time at time scales shorter than a single optical cycle. These systems conserve momentum but not energy, and are characterized by momentum bands and bandgaps where the amplitudes of their eigenmodes can increase or decrease exponentially. The fundamentals of PTCs will be introduced along with the classical and quantum features of light-matter interactions in PTCs. Among these, the most notable is the emission of light in PTCs, which opens new avenues for making widely tunable lasers that do not rely on any atomic resonance and draw their energy from the temporal modulation of the medium. Another important feature is the quantum aspects, which yield a plethora of fundamental features ranging from the generation of pairs of entangled photons, controlling spontaneous emission through the temporal modulation, and creating 2D cluster states. Finally, recent experimental progress on modulation shorter than a single cycle will be presented, focusing on the recent breakthrough of observing time-reflection at optical frequencies. Last but not least, nonlinear optics in such time-varying media will be discussed, envisioning new mechanism for high harmonic generation in solids that can yield large photon flux.
Tuesday, 26 May 2026
11:00
Astrophysics Seminar
Philipp Mertsch
Galactic cosmic rays as an interstellar laboratory
Central seminar room, library building
Cosmic rays are a fundamental component of the Galactic ecosystem and offer insights that reach beyond the Milky Way, including how galaxies form and evolve. They also serve as probes for new physics, such as dark matter and primordial antimatter. However, all such investigations hinge on resolving the century-old question of cosmic-ray origin. Over the last decade and a half, space-based missions like AMS-02, CALET, and DAMPE have delivered a wealth of data; more recently, the ground-based LHAASO has provided high-precision measurements of protons and helium. Modeling these observations enables inferences about the classes of cosmic-ray sources and the conditions that govern their propagation -- for example, transport through turbulent magnetic fields. The emerging picture is quite intricate, suggesting that prevailing models must be revised, if not completely reworked. I will highlight recent advances in modelling Galactic cosmic rays from stochastic source populations and explore the implications for diffuse emission. A specific class of such models are motivated by evidence for inhibited diffusion around Galactic cosmic-ray sources. If time permits, I will also review recent findings on the transport of magnetic field lines and particles in synthetic turbulence.
16:30
Heidelberg Joint Astronomical Colloquium
Douglas Lin
Stellar evolution & black hole coagulation in AGNs: an analogue of planet formation
Active galactic nuclei are mostly powered by inflow through accretion disks onto central supermassive black holes. Beyond a few times their Schwarzschild radius, gravitational instability in these disks leads to self-regulated formation and evolution of massive stars which chemically enrich their neighborhood along with stellar-mass black holes. These compact remnants are captured by coexisting massive main sequence stars, form close binaries, readily merge, and excite intense gravitational waves with potentially observable electromagnetic signatures. The massive stars' migration, with or without black hole cores, efficiently transporting mass regardless of the Eddington limit and promoting the rapid growth of supermassive black holes in the early Universe. Analogous physical processes are also relevant in the context of planet formation in protostellar disks. They account for the persistent super-solar metallicity, especially in Nitrogen and iron, inferred from broad emission lines of high and low redshift AGNs. To arrange a visit with the speaker during the visit, please contact their host: Haochang Jiang
17:00
Particle Colloquium
Anke Ackermann
ZZy Results
Physikalisches Institut INF 226, Konferenzraum 1-3 (Room 00.101 bis 00.103)
Measurement of ZZ? production with the ATLAS detector Anke Ackermann1 1 Kirchhoff-Institute for Physics, Heidelberg University Abstract The Standard Model of particle physics predicts the rare production of triboson final states, offering a unique probe of gauge boson selfinteractions and sensitivity to anomalous quartic gauge couplings. We present the measurement of ZZ? production, utilizing the large dataset collected by the ATLAS detector during Run 2. The analysis focuses on the fully leptonic final state, pp ? ZZ? ? ?+ ?? ??+ ??? ? with ?, ?? = e or µ. Evidence for the ZZ? production has been observed with eight candidate events and an expected background of less than one event. The measured cross-section of ?ZZ? = 0.144 ± 0.058 (stat.) ± 0.006 (syst.) fb is consistent with Standard Model predictions. To achieve this result, we develop a novel method to estimate the dominant background from non-prompt photons produced within jets, using a jet ratio technique to extrapolate from a high-statistics control region. This talk will summarize the analysis strategy, background estimation, and cross-section measurement, highlighting the potential for future analysis to probe new physics in the electroweak sector. 1
Wednesday, 27 May 2026
09:30
Seminar Dynamik und Struktur von Atomen und Molekülen
Dr. Marta Murillo Sanchez; Ultrafast Liquid Crystal Dynamics
tba
Central seminar room, library building
11:15
Gentner Colloquium for Astroparticle Physics
Dr. Alex Kavner (University of Zurich)
Super Lindhard ionization from sub-keV nuclear recoils: implications for CEvNS and dark matter searches
Central seminar room, library building
Germanium is an essential element for the advancement of nuclear and particle physics. High purity germanium detectors are utilized across diverse experiments including: neutrino-less double beta decay, coherent elastic neutrino nuclear scattering (CEvNS), dark matter searches, nuclear decay experiments, and many others. Full understanding of detector response to low energy nuclear recoils is of high importance being primary signature of both CEvNS and dark matter. Several recent measurements have probed the ionization produced by 254 eVnr nuclear recoils and found a significant enhancement over the theoretical prediction. These results will be discussed as well as their relevance for existing CEvNS experiments and the upcoming TESSERACT dark matter experiment.
15:00
Special Seminar
Prof. Agapi Emmanouilidou; University College London
Delay times and Coulomb explosion imaging in interaction of small molecules with XFEL pulses
Central seminar room, library building
16:30
Zentrum für Quantendynamik Kolloquium
Prof. Adam Rançon
Observation of the Anderson transition in a 4D quantum system with synthetic dimensions
Molecular Ground-State Fluctuations: Subtle Feature, Large Impact
Central seminar room, library building
ARI Institute Colloquium
Zofia Kaczmarek
The secret lives of isolated stellar remnants
ARI, Moenchhofstrasse 12-14, Seminarraum 1.OG
Microlensing has long been a powerful tool for studying dark objects, but its full potential has yet to be unlocked. Typically, information about the lens comes solely from the light curve, which is subject to strong degeneracies. In addition to increasing the observed brightness of the background star, microlensing also produces tiny shifts in its apparent position  a phenomenon known as astrometric microlensing. This effect can break degeneracies and, crucially, allows for direct measurement of the lens mass. Thanks to recent advances in astrometry, detecting these subtle shifts is now becoming possible. Until now, astrometric microlensing has yielded only a handful of detections, which required expensive, targeted follow-up. This year, the field will reach two major milestones. The Roman Space Telescope, the first space mission designed for microlensing observations, is set to launch this autumn. Later in the year, Gaia Data Release 4 will, for the first time, provide astrometric time-series data for nearly two billion sources. These new datasets will finally make it possible to build a systematic census of isolated dark stellar remnants in the Milky Way. Using detailed simulations, we have explored how to identify dark remnants, optimize the use of observation and analysis resources, and extract masses from astrometric signals. I will discuss these efforts and showcase the exciting developments that lie ahead in 2026.
