Fernando Granha Jeronimo

Assistant Professor in Computer Science at the Siebel School at University of Illinois Urbana-Champaign.

Portrait of Fernando Granha Jeronimo

About me

My research is in theoretical computer science (TCS), mainly involving:

  • Coding Theory
  • Expanders and High-dimensional Expanders
  • Optimization, such as the Sum-of-Squares hierarchy
  • Quantum Computing

Interactions among these areas are very present in my research. In particular, I love expansion (broadly defined) since it provides an amazing lens to explore and understand phenomena in all the above areas. I am also particularly intrigued by the many connections between CS theory and mathematics. Glimpses on some of my interests in coding theory and expanders can be found in short talks at IAS here and here.

I am looking to continuously grow my research group over the years. Motivated students are encouraged to apply to our graduate programs.

Email: granha[at]illinois[dot]edu

PhD Students

Lenny Liu

William Gay (co-advised with Makrand Sinha)

Ricardo Garcia (co-advised with Makrand Sinha)

Abhi Shukul (co-advised with Makrand Sinha)

Papers


Optimal Proximity Gap for Folded Reed-Solomon Codes via Subspace Designs
(with Lenny Liu and Pranav Rajpal)


Probabilistic Guarantees to Explicit Constructions: Local Properties of Linear Codes
(with Nikhil Shagrithaya) - STOC 2026


A Framework for CSPs over the Hypercube: from Sublinear to Subexponential Time
(with Agastya Vibhuti Jha and Davide Mazzali)


List Decoding Expander-Based Codes via Fast Approximation of Expanding CSPs: I
(with Aman Singh)

Higher-order Delsarte Dual LPs: Lifting, Constructions and Completeness
(with Leonardo Nagami Coregliano, Chris Jones, Nati Linial and Elyassaf Loyfer) - ITCS 2026



Pseudorandomness of Expander Walks via Fourier Analysis on Groups
(with Tushant Mittal and Sourya Roy) - RANDOM 2025


Explicit Codes approaching Generalized Singleton Bound using Expanders
(with Tushant Mittal, Shashank Srivastava and Madhur Tulsiani) - STOC 2025 (invited to special issue)
[slides @CS Seminar]


List Decoding Explicit Binary Codes Near Capacity at (semi-)Structured Centroids
(Fernando Granha Jeronimo)


Coherence in Property Testing: Quantum-Classical Collapses and Separations
(with Nir Magrafta, Joseph Slote and Pei Wu) - QIP 2025
[video @QIP'25]


List Decodable Quantum LDPC Codes
(with T. Bergamaschi, T. Mittal, S. Srivastava and M. Tulsiani) - QIP 2025 (poster)


Pseudorandom and Pseudoentangled States from Subset States
(with Nir Magrafta and Pei Wu) - TQC 2024 (poster)


Dimension Independent Disentanglers from Unentanglement and Applications
(with Pei Wu) - CCC 2024


List Decoding of Tanner and Expander Amplified Codes from Distance Certificates
(with Shashank Srivastava and Madhur Tulsiani) - FOCS 2023


The Power of Unentangled Quantum Proofs with Non-negative Amplitudes
(with Pei Wu) - STOC 2023 (QIP 2024)
[video @STOC'23]


Fast Decoding of Explicit almost Optimal \(\epsilon\)-balanced \(q\)-ary Codes and
              Fast Approximation of Expanding \(k\)-CSPs
(Fernando Granha Jeronimo) - RANDOM 2023


Exact Completeness of LP Hierarchies for Linear Codes
(with Leonardo Nagami Coregliano and Chris Jones) - ITCS 2023
[video @ITCS]


Almost Ramanujan Expanders from Arbitrary Expanders via Operator Amplification
(with Tushant Mittal, Sourya Roy and Avi Wigderson) - FOCS 2022 (invited to special issue)
[video @IAS] [video @Princeton]


A Complete Linear Programming Hierarchy for Linear Codes
(with Leonardo Nagami Coregliano and Chris Jones) - ITCS 2022
[video @IAS]


Explicit Abelian Lifts and Quantum LDPC Codes
(with Tushant Mittal, Ryan O’Donnell, Pedro Paredes and Madhur Tulsiani) - ITCS 2022
[video @IAS]


Near-linear Time Decoding of Ta-Shma's Codes via Splittable Regularity
(with Shashank Srivastava and Madhur Tulsiani) - STOC 2021
[video @STOC'21] [slides @STOC'21] [video @JTW'20] [slides @Junior Theorists Workshop'20]


Unique Decoding of Explicit \(\epsilon\)-balanced Codes Near the Gilbert-Varshamov Bound
(with Dylan Quintana, Shashank Srivastava and Madhur Tulsiani) - FOCS 2020 (invited to special issue)
[longer video @FOCS20] [longer slides @FOCS20] [slides general CS audience]


Sum-of-Squares Lower Bounds for Sherrington-Kirkpatrick via Planted Affine Planes
(with Mrinalkanti Ghosh, Chris Jones, Aaron Potechin and Goutham Rajendran) - FOCS 2020


Tighter Bounds on the Independence Number of the Birkhoff Graph
(with Leonardo Nagami Coregliano) - European J. of Combinatorics


List Decoding of Direct Sum Codes
(with Vedat Levi Alev, Dylan Quintana, Shashank Srivastava and Madhur Tulsiani) - SODA 2020
[slides @SODA20]


Approximating Constraint Satisfaction Problems on High-Dimensional Expanders
(with Vedat Levi Alev and Madhur Tulsiani) - FOCS 2019

Other Writings

A Constrained Random Walk Through Coding Theory
(Fernando Granha Jeronimo) - Dissertation

Short Bio

Prior to UIUC, I was a Simons-Berkeley fellow kindly hosted in Venkatesan Guruswami's group, and thankfully supported in part as a Google Research Fellow. I had a wonderful experience as a postdoc in Avi Wigderson's group at the Institute for Advanced Study (IAS). I obtained my PhD from UChicago. I received a B.Sc. and M.Sc. degrees from Unicamp Brazil (my home country) and also received an engineering degree from Telecom Paris (France) as part of a double degree program.

Local-to-Global Mentorship Program

Local-to-Global TCS Mentorship Program at UIUC

Past Teaching Activities

I was a TA 14 times for various courses during my PhD receiving two (annual) TA prizes from the CS department.

2026 Fernando Granha Jeronimo