Deep learning researcher · PhD, Technion (2026)

Models for hard-to-measure signals, with the physics and physiology built in.

My research is about deep learning for real-world temporal and spatiotemporal data: signals that are noisy, partly missing, and collected far from the lab. I bring the structure of the domain, whether physiology, physics, or network behavior, into modern models so they are not only accurate but interpretable and reliable, and I apply the same lens to large language models, asking what they actually compute rather than trusting their headline scores. I completed my PhD at the Technion in 2026 with Alex Bronstein and Reuven Cohen, and spent 2026 as an independent contractor with Apple's Video Engineering group.

Open to research scientist and applied scientist roles in LLM understanding, physics-informed AI and sensing.

Barak Gahtan
2 × ACML 2026First-author papers on LLM depth and attentionSGP 2026Differentiable eikonal solvers, Computer Graphics ForumICMI 2025 · oralFirst instantaneous VO₂ from a consumer smartwatchTechnion · ApplePhD in Computer Science; independent contractor, Apple Video Engineering

Selected work

All 13 publications
ACML 2026 · PMLR

The Residual Stream's Effective Depth

Barak Gahtan, Ido Galil, Alex M. Bronstein

A calibrated scalar for how much of a transformer's depth is distinct computation: fifteen of sixteen decoder-only models fall below the orthogonal-update reference, and matched controls trace the gap to correlated residual updates.

Computer Graphics Forum · SGP 2026

Differentiable Randers-Finsler Eikonal Solvers

Barak Gahtan, Jacob Shpund, Alex M. Bronstein

A GPU fast-sweeping solver made exactly differentiable through implicit differentiation, used to recover anisotropic metrics from sparse arrival times and learn spread models on real wildfire perimeters.

Research themes

  • What transformers actually compute

    Calibration-free diagnostics that audit a model instead of trusting its headline scores: how much of its depth is distinct computation, whether a personalized model conditions on the user at all, and where pre-scoring query-key geometry helps attention.

  • Differentiable physics and inverse problems

    Classical solvers kept inside the learning loop. Implicit differentiation through fast sweeping turns anisotropic Eikonal distance fields into trainable models of wildfire spread.

  • Physiology from low-friction signals

    Instantaneous VO₂ and cardiovascular load estimated from smartwatches, chest straps and monocular 3D pose in video, with neural ODE and Kalman structure and four datasets collected in the field.

  • Encrypted network traffic as time series

    QUIC traces rendered as image sequences and multi-operator cellular links as multivariate series, from a 100,000-trace public dataset to real-time network selection for teleoperated vehicles.