### 2024 Leinweber Fellows

**Postdoctoral Fellows**

I am thrilled to join the Leinweber Center for Theoretical Physics as a Postdoctoral Fellow under the mentorship of Prof. Finn Larsen this fall. Hailing from Hyderabad, India, I completed a dual BS-MS degree in Physics and Mathematics at the Indian Institute of Science Education and Research, Thiruvananthapuram (IISER-TVM). I then pursued a PhD at the Tata Institute of Fundamental Research, Mumbai, under the guidance of Prof. Abhijit Gadde. My research interests include various aspects of Holography, Black Holes, and Quantum Information Theory, and I am eager to further explore these areas during my term at the LCTP.

Growing up in Poland, I embarked on my academic journey at Jagiellonian University in Krakow, where I earned my bachelor's degree. After graduation, I moved to the UK to pursue the master’s degree at the University of Cambridge. Currently, I am completing my doctoral degree at the University of Maryland under the mentorship of Professor Anson Hook. This Fall, I am excited to join the University of Michigan as a Leinweber Postdoctoral Fellow, where I will be collaborating with Professor Aaron Pierce. My research interests include gravitational wave astronomy, ultralight field phenomenology, and model building.

**Graduate Fellows**

I’m a third-year student working with Leopoldo Pando Zayas. Originally from western PA, I completed my undergrad work at UC Berkeley before coming here to Michigan. Broadly speaking, my research is centered on the AdS/CFT correspondence, which describes a relationship between certain gravity theories and quantum field theories. Much of my work has focused on entanglement entropy, a field-theoretic quantity that can be understood in terms of minimal surfaces on the gravitational side of the correspondence. Entanglement entropy is, among other things, a valuable tool for understanding information-theoretic properties of black holes as well as characterizing how quantum field theories flow with energy scale. I am also interested in the superconformal index, a quantity that counts states in certain field theories. In some AdS/CFT setups, the index may be understood gravitationally in terms of brane-like objects known as giant gravitons.I’m very grateful to the Leinweber family who is generously supporting my work. Outside of physics I enjoy running and also have an interest in medieval, renaissance, and baroque music.

**Summer Research Awards**

I am a second year student working with Prof. James Liu. I grew up in the south Indian state ofKerala and obtained my undergraduate degree from the Indian Institute of science education and research (IISER) at Pune. My work so far is centered on understanding the higher derivative corrections to supergravity. Supergravity can be thought of as low energy descriptions of string theory. So when we compactify supergravity, many of the interesting features of strings can be expected in the resulting description. Under Prof. Jim’s supervision, I tried to understand one such particular aspect, namely T-duality and how it is manifest in the lower dimensional picture. I am also interested in seeing how such features come from a bottom up approach. Besides physics I also enjoy listening to classical music and making pencil drawings.

.I’m a third year student working for Professor Henriette Elvang, studying scattering amplitudes. I got my undergraduate degree in Physics and Mathematics at Williams College. The focus of my research is finding S-matrix bootstrap bounds on effective field theories, trying to learn how fundamental physical assumptions constrain the physics we observe at low energies. Currently, my work focuses on identifying low-energy features of string theory that lead to it being the only compatible UV completion of an EFT.

I am a second-year PhD candidate working with Prof. Dragan Huterer and Prof. Camille Avestruz. My research interests lie in theoretical cosmology, with a focus on dark energy, modified gravity, data analysis, and the Hubble constant tension. My current project involves cross-correlating dark siren gravitational wave events with their corresponding photometric galaxy data in a novel approach to constrain the Hubble constant. This research is pivotal in addressing the Hubble constant tension, where measurements from the “early” and “late” universe differ in their constraints of how quickly the universe is expanding due to dark energy. Additionally, I am engaged in analyzing the first year's data from the Dark Energy Spectroscopic Instrument (DESI) survey, which has produced the largest 3D map of the universe to date. I am also involved in deriving and implementing the initial conditions for a wide range of modified gravity (Horndeski) models, which will be applied to analysis of data from the cosmic microwave background.

In 2021, I graduated from MIT with a BS in Physics and Mathematics. I took this quantitative knowledge with me to the University of Michigan, where I am working in the Physics PhD program at LSA. As a graduate student, my current research focuses on high-energy theory in the Leinweber Center for Theoretical Physics. I am currently working with Professor Ratindranath Akhoury on these current research interests: entanglement entropy as how it relates to UV-IR mixing, dressings and asymptotic symmetries in QFT, and electromagnetic and gravitational memory.

Evan grew up in western Massachusetts, completed his undergraduate degree at Johns Hopkins, and is currently a third-year PhD candidate working with Professor Aaron Pierce. Evan is broadly interested in Beyond the Standard Model (BSM) phenomenology and early universe cosmology. Currently, Evan is working on two projects related to dark matter. In one project, he is studying how modern experiments constrain the parameter space for models of weak-scale dark matter. In the other project, he is studying early universe production mechanisms for dark matter of lower mass. In particular, he is interested in cases where there are additional invisible particles with which the dark matter can interact. Evan is super excited to continue his work this summer, and would like to extend his gratitude to the Leinweber family for their generous support.

Emery Trott is a graduate student working with Professor Dragan Huterer. His work focuses on techniques for combining dark siren gravitational wave events with galaxy surveys to measure the Hubble constant. This work can provide an independent perspective on the outstanding Hubble tension, which may point to new physics beyond the standard LCDM cosmological model.

Eddie Aljamal is a third year PhD student working in theoretical Cosmology working with Professor August Evrard while also obtaining Michigan Institute for Data Science (MIDAS) and Michigan Institute of Computational Discovery and Engineering (MICDE) certificates focusing on deep learning and computer vision. The mass of galaxy clusters is an essential ingredient in measuring the halo mass function (HMF) which in turn provides constraints on cosmological parameters and tests the fundamental theories of gravity. Eddie is helping to develop methods to improve measurements of cluster mass by 1) studying the dynamical mass of clusters in the SDSS catalog in order to provide improved measurements of the galaxy velocity bias, 2) Calculating mass proxy scaling relations and well as mass proxy quality for clusters in the Local Volume Complete Cluster Survey (LoVoCCS) and in state-of-the-art hydrodynamical simulations, 3) creating an AI-accelerated data analysis pipeline to rapidly and efficiently estimate the mass of galaxy clusters by leveraging the distortions of background galaxies--caused by the gravitational lensing effect of foreground clusters.

I am a fourth-year graduate student working with Professor Henriette Elvang on scattering amplitudes, specifically focusing on the bootstrap program. Scattering amplitudes are the observational predictions of theoretical models, describing the interactions of particles. It is known that not every form of scattering amplitudes can be reasonably constructed. They are constrained by certain consistency requirement of our model, including locality, causality, and unitarity. We are interested in explicitly solving these constraints in a various setup, capturing the allowed parameter region of physic models. We are also working on implementing additional assumptions such as the lowest mass spectrum and understanding how would it affect the allowed theoretical region. **Alan will defer his funding to Fall 2024**

My name is Deric Jones, and I am a first-year PhD student in the Department of Physics. Prior to this, I completed my Bachelor’s and Master’s of Science in Physics at Rensselaer Polytechnic Institute. My work entails studies of galaxy clusters and their host dark matter halos as probes for cosmology. In particular, I am interested in the triaxial signatures of the shapes of galaxy clusters in cosmological simulations and big survey data, from collaborations such as the Dark Energy Science Collaboration of the Rubin Observatory’s Legacy Survey of Space and Time. Triaxial signatures can give insight into how galaxy clusters grow and how observables relate to their surrounding environment. For example, the distribution of member galaxies can point to the splashback radius, where accepted matter turns around and creates a dark matter halo. This feature of a dark matter halo encodes information about cosmological parameters about the expanding Universe. I hope to explore connections between signatures of growth in simulations with observational data.

**Graduating Students**

I'm a graduating PhD student working with Jim Liu. My research mainly falls under precision holography, pushing our understanding of the AdS/CFT correspondence to finite N. I have primarily focused on the (super)gravity side of the correspondence, including recent work on consistent truncations of higher-derivative supergravity, holographic renormalization group flows across dimensions, and the giant graviton expansion of the N=4 super Yang-Mills index from bubbling geometries.

As part of my doctoral research, I have worked on a systematic analysis of some of the properties of supersymmetric black holes, as part of a broader goal of reconciling the two conceptual pillars of modern physics: gravity and quantum mechanics. Despite the centrality of these black holes in the contemporary work on quantum gravity, they present many aspects that are not well understood, such as their thermodynamical properties, their full spacetime-dependence, as well as their potential instabilities of deviations from them. The approach of my research has been to probe these features and systematize our understanding thereof.