Boryana Hadzhiyska
Postdoctoral Fellow
UC Berkeley and LBNL
Talk Title: Solving small-scale problems with large-scale physics
Bio: I originally come from Sofia, Bulgaria, and am currently a joint postdoctoral fellow at University of California, Berkeley, and Lawrence Berkeley National Lab, where I work on various concepts in theoretical cosmology, including the joint analysis of large-scale structure and cosmic microwave background (CMB) probes. In my free time, I like biking to quiet places in nature, singing, reading, learning new languages, supporting social justice issues as well as I can, and eating lots of desserts!
Research Interests: Cosmology is one of the fastest developing fields in physics: cutting-edge telescopes such as DESI are in the process of building the largest map of galaxies in the Universe, while Cosmic Microwave Background (CMB) experiments are creating the most detailed image of the afterglow of the Big Bang. These experiments provide us with copious amounts of data to address long-standing questions such as ‘What is the composition of the Universe?’, ‘What is the nature of dark matter and dark energy?’ and ‘What is the mechanism of inflation?’. The best path forward to addressing these mysteries lies in the powerful combination of late- and early-Universe probes, where our statistical power is unprecedented. This has been the focus of my work: charting out the low-density gas distribution in the Universe – a decade-long issue known as the ‘missing baryon’ problem – via joint CMB and galaxy analysis. In the next couple of years, I plan to address these problems: what is the distribution of gas in the Universe, what is the strength of supermassive black hole activity, what is the growth rate of structure, and what do particle interactions in the early Universe look like.
Daniela Koeck
Postdoctoral Researcher
University of Oregon
Talk Title: Shining light on dark matter with the LHC
Bio: Daniela Koeck is a postdoctoral researcher at the University of Oregon. As part of the ATLAS and FASER collaborations, she is an experimental particle physicist focussing on understanding dark matter and its potential particle candidates. Originally from Germany, she completed her Bachelor and Master degree in Munich before moving to the United Kingdom for her Ph.D. at the University of Sussex. She is currently based at CERN, Switzerland, where she combines work on searches for new physics, detector operations, detector upgrades and outreach.
Research interests: My research as experimental particle physicist is driven by a deep curiosity to explore and connect large-scale phenomena to fundamental particle interactions, and to investigate the nature of dark matter. With the high-energy proton collisions provided by one of the largest machines ever built, the Large-Hadron-Collider (LHC) at CERN, we can recreate the conditions of our universe just after the Big Bang.
With the ATLAS experiment, we have the ability to look for traces of new particles predicted by various theoretical models, potentially discovering new physics. Considering Supersymmetry as prime example: in particular production at electroweak scales still presents a wide-open field of unexplored possibilities for dark-matter candidates.
The FASER experiment located downstream from ATLAS extends the possibilities for searches at the LHC, allowing exploration of long-lived particles. This broadens the target from promptly decaying, singular dark matter to entire sectors of 'dark' particles only interacting with known particles through light mediators.
Towards future improvements of the LHC and searches for new physics, upgrades to the ATLAS 'trigger' system, selecting crucial collision data, are essential. As part of my research, I develop novel trigger algorithms to ensure full exploitation of the High-Luminosity LHC potential.
Elise LePage
Ph.D. Student
UC Berkeley
Talk Title: Homological Link Invariants from String Theory
Bio: I am currently a sixth year PhD student at University of California, Berkeley working in mathematical physics, advised by Professor Mina Aganagic. I will be graduating this spring, and moving to Columbia University, where I will be a Simons Junior Fellow. My work focuses on the intersection between string theory, low-dimensional topology, and representation theory. My PhD thesis develops methods for computing homological link invariants using categories of A-branes. Besides physics and mathematics, I enjoy hiking, running, rock climbing, and generally being in outdoors.
Research Interests: My research centers on the intersection between string theory and geometry. I study homological mirror symmetry and especially the topological A-model with an eye towards low-dimensional topology and categorical representation theory. My PhD thesis uses categories of A-branes to categorify the link invariants computed by Chern-Simons theory. I have developed many tools to better understand these categories of A-branes and to systematically compute homological link invariants for any representation and Lie algebra. I am now applying these tools to broader problems, such as categorifying quantum groups and their representations using categories of A-branes. My future research goals revolve around continuing to develop my collection of techniques for understanding categories of A-branes and applying these techniques to investigate problems in both physics and mathematics. A highly promising application is to produce new 3- and 4- manifold invariants in this way, by cutting and gluing the target spaces of different A-models and by categorifying invariants of knot complements.
Chloe Lindeman
Postdoc
Johns Hopkins University
Talk Title: Hysteresis across scales: memory and flow in grains, glasses, and biology
Bio: I am interested in the self-organization of soft, active, and living systems in response to complex driving. Even passive systems like granular materials can undergo changes when perturbed, reorganizing their structure in subtle ways that encode a memory of deformation. The plot thickens with the addition of active or living agents, which can both shape and be shaped by the features and flows of surrounding material. How does the interplay between structure and activity lead to pattern formation? What guiding principles emerge in these deeply out-of-equilibrium systems? And what do such systems teach us about the bio-geo-physical world we inhabit?
Research Interests: Chloe Lindeman received her PhD with Sid Nagel at the University of Chicago, where she focused on memory effects in granular material. Now an independent postdoc at Johns Hopkins University, she collaborates with the groups of Dan Reich and Bob Leheny in physics to study bacterial swimming in complex fluids, and with the lab of Rebecca Schulman in chemical engineering, where she uses DNA to build tunable dynamical systems.
Jinghui Liu
Postdoctoral Researcher
Max Planck Institute for the Physics of Complex Systems (MPI-PKS)
Talk Title: Electrical signalling and growth control across living organisms
Bio: Jinghui Liu is a postdoctoral researcher in experimental biological physics, supported by an ELBE fellowship at the Max Planck Institute for the Physics of Complex Systems and a Marie Skłodowska-Curie fellowship at the Max Planck Institute for Molecular Cell Biology and Genetics. Jinghui holds a Bachelor from Peking University, China. She earned her PhD from Massachusetts Institute of Technology in 2022, studying topological and geometric orders of nonlinear signalling processes in dividing cells. In her postdoctoral work in Germany, she is working to understand the physics of electrical signals in regenerative tissues. Jinghui enjoys cooking and cat-sitting in off-work time.
Research Interests: As an interdisciplinary scientist, I am interested in the physical organization of various forms of signals processed by cells and tissues to properly divide, grow and repair. Specifically, I ask the question: do we understand how signals generically orchestrate, without noting the identities of the entities? To this end, I work on experimental approaches to perform quantitative live measurements for key electric, chemical and mechanical signals, as well as analysis tools that allow for the systematic extraction of unconventional order parameters. Employing such characterization, I collaborate closely with soft condensed matter scientists to hand-in-hand develop predictive theory. Ultimately, I aim to design physics-inspired state perturbations that allow for minimal-invasive, maximal-versatile controls of physiological outcomes.
In my PhD work, I used a chemo-mechanical signalling process in sea star oocytes to practice above ideas at the cell-level. This cell-surface signal transmission process, when I resolved to its topological order, turns out intriguingly simplifies to a class of two-dimensional turbulence driven by pairwise vortex forcing. When modulating the signalling state via an engineered light-activatable switch, I found that its nonlinear excitability translates to a phase space of versatile surface deformation dynamics. In my postdoctoral work, I started investigating the dynamics and function of ionic currents that underlie bioelectric signal organizations after organ damage. My work now uses zebrafish embryos as the animal-level model, which allows me to assess regenerative impacts.