Written Work

Visualizing How the Structure of Large-Radius Jets Shapes Their Wakes

Arjun Kudinoor, Daniel Pablos, Krishna Rajagopal

Jan 30, 2025 (arXiv: 2501.18683)

The ATLAS Collaboration has developed a method to analyze large-radius jets composed of skinny R = 0.2 subjets in heavy-ion collisions. We first demonstrate that the measurements pioneered by ATLAS constrain the value of the resolution length of QGP -- and rule out any picture in which an entire parton shower loses energy coherently as a single entity. We then analyze the response of the medium to the passage of large-radius R=2 jets containing two skinny subjets in gamma-jet events. We introduce novel jet-shape observables that allow us to visualize how the internal structure of large-radius jets shapes the wakes they excite in the QGP. We find that even when the subjets are ∼0.8 radians apart, the angular shape of the soft hadrons originating from their wake forms a single broad structure. Only when the two subjets are even farther apart are two sub-wakes revealed. We show that the way in which jet structure shapes the structure of jet-induced wakes can be visualized with similar clarity in experiments by using only low-pT hadrons. The observables we introduce offer a new and distinctive way of seeing jet-induced wakes -- and wake substructure -- in heavy-ion collision data.

Imaging the Wakes of Jets with Energy-Energy-Energy Correlators

Hannah Bossi, Arjun Kudinoor, Ian Moult, Daniel Pablos, Ananya Rai, Krishna Rajagopal

Dec 10, 2024 (doi: 10.1007/JHEP12(2024)073)

July 18, 2024 (arXiv: 2407.13818)

We use the hybrid strong/weak coupling model of heavy ion collisions to simulate interactions between energetic sprays of particles and the quark gluon plasma (QGP) that is created after a high-energy collision between large nuclei. These sprays of particles (called jets) leave behind wakes in the QGP. We show that hadrons originating from wakes are the dominant contribution to the three-point energy correlation function in the regime where the three points are well-separated in angle, forming a roughly equilateral triangle. This equilateral region of the correlator is far from the region populated by collinear emissions in the absence of QGP (the vacuum), making this equilateral region a canvas on which jet wakes can be imaged. Our work is a key step towards the systematic use of energy correlators to image and unravel the dynamical response of a droplet of QGP to a passing jet.

Geometry and Gauge-Theoretic Physics: An Instanton Connection

Arjun Kudinoor

March 31, 2023

My senior thesis on differential geometry and gauge theory in physics. I focus on the study of the Yang--Mills equations, their self-dual solutions (instantons), and a proof of the Atiyah--Hitchin--Singer theorem of SU(2)-instantons on the 4-sphere.

Thesis Advisor: Mike Miller Eismeier, Columbia University

This thesis was awarded the John Dash Van Buren Jr. Prize in Mathematics by Columbia University for being the best undergraduate thesis submitted in 2023.

Breaking Space Inversion-Symmetry to Obtain Asymmetric Spin-Wave Excitation in Systems with Nonuniform Magnetic Exchange

Rair Macêdo, Arjun S. Kudinoor, Karen L. Livesey, Robert E. Camley

September 12, 2021 (doi: 10.1002/aelm.202100435)

The consequences of non-uniform exchange in magnetic systems are reported. A linearly varying exchange interaction is used along a magnetic strip as a route to spatial inversion symmetry-breaking. It is found that, in addition to asymmetric modes and localization, spatially varying exchange can be used to design nonreciprocal magnetic signal excitation at frequencies that are tunable.

Research Mentor: Robert Camley, University of Colorado at Colorado Springs

Bridging Partitions Between Statistical Mechanics, Quantum Mechanics, and Black Holes

October 27, 2024

A translation between the partition function of a canonical ensemble in thermal equilibrium and the partition function of an ensemble of quantum mechanical fields using a path integral formulation of quantum mechanics. An application to deriving the Hawking temperature of black holes is described.

Supersymmetry and The Witten Index

Spring 2023 - PHYS 3500 Independent Readings in Supersymmetry and AdS/CFT

A formulation of supersymmetric quantum mechanics and the Witten index. Relations between the Atiyah-Singer index theorem for chiral operators and the Witten index for N=1 supersymmetric nonlinear sigma model are discussed.

The Dirac-von Neumann and Hilbert Space Formulations of Quantum Mechanics

Fall 2021 - MATH 4051 Topology

A study of Banach spaces, Hilbert spaces, and C* Algebras. The Dirac von-Neumann and Hilbert space formulations of Quantum Mechanics are described and related.

Violating the CHSH Inequality Using Entangled Photons

Fall 2023 - PHYS 3081 Intermediate Physics Laboratory

An experimental demonstration of violating the CHSH-Bell Inequality using entangled photons. I was lucky to conduct this experiment as the 2022 Nobel Prize was awarded to Aspect, Clauser, and Zeilinger for their work on photon entanglement experiments.

The Variational Quantum Eigensolver and Perturbation Theory

Spring 2022 - PHYS 6038 Quantum Mechanics II

A lecture on the variational principle, perturbation theory, and a simple example of the variational quantum eigensolver on Qiskit.

Quantum Teleportation Protocol for an Arbitrary n-Qubit State

Summer 2021 - PHYS 3084 Quantum Simulation and Computing

Formulation of a protocol to teleport an arbitrary n-qubit state using a 2n-qubit binary-inspired intermediary channel-state. The protocol was encoded on Qiskit and tested on IBM's qasm_simulator and quantum hardware.

The Fundamental Theorem of Riemannian Geometry

Fall 2021 - MATH 4081 Differentiable Manifolds

Formulation and proof of the Fundamental Theorem of Riemannian Geometry. Includes a study of Affine connections, Riemannian connections, and Riemannian manifolds

Quaternion Algebras

Fall 2021 - MATH 4042 Modern Algebra

A study of quaternions, quaternion algebras, and biquaternions

Calculating Geometric Series using Game Show Taxes

One can calculate geometric series without needing to use algebra or calculus. Instead, an understanding of game show taxes will suffice. This article demonstrates how this is the case.

The Golden Rule of Agile Estimation: Fibonacci Story Points

An exploration of different scales of story points, and a focus on the Fibonacci scale and its connection to the golden ratio