About

I’m an Assistant Professor (aka Senior Lecturer) in the School of Computer Science at Tel Aviv University since Fall 2019. Previously, I was a Senior Research Scientist at Google Brain, Mountain View. I received my PhD in December 2016 from the Technion—Israel Institute of Technology, where my advisor was Prof. Elad Hazan.

My research interests are in machine learning and optimization.


Publications

Full Matrix Preconditioning Made Practical.
Rohan Anil, Vineet Gupta, Tomer Koren, Kevin Regan, Yoram Singer.
Preprint; preliminary version in NeurIPS’19 Workshop on “Beyond First Order Methods in ML”

Private Stochastic Convex Optimization: Optimal Rates in Linear Time.
Vitaly Feldman, Tomer Koren, Kunal Talwar.
Preprint; preliminary version in NeurIPS’19 Workshop on “Privacy in Machine Learning” (PriML’19)

Revisiting the Generalization of Adaptive Gradient Methods.
Naman Agarwal, Rohan Anil, Elad Hazan, Tomer Koren, Cyril Zhang.
Preprint; preliminary version in OPT2019

Memory-Efficient Adaptive Optimization.
Rohan Anil, Vineet Gupta, Tomer Koren, Yoram Singer.
NeurIPS 2019, to appear
[arXiv]

Robust Bi-Tempered Logistic Loss Based on Bregman Divergences.
Ehsan Amid, Manfred K. Warmuth, Rohan Anil, Tomer Koren.
NeurIPS 2019, to appear
[arXiv]

Better Algorithms for Stochastic Bandits with Adversarial Corruptions.
Anupam Gupta Tomer Koren, Kunal Talwar.
COLT 2019
[arXiv]

Learning Linear-Quadratic Regulators Efficiently with only $\sqrt{T}$ Regret.
Alon Cohen, Tomer Koren, Yishay Mansour.
ICML 2019
[arXiv]

Semi-Cyclic Stochastic Gradient Descent.
Hubert Eichner, Tomer Koren, Brendan McMahan, Nathan Srebro, Kunal Talwar.
ICML 2019
[arXiv]

Online Linear-Quadratic Control.
Alon Cohen, Avinatan Hassidim, Tomer Koren, Nevena Lazic, Yishay Mansour, Kunal Talwar.
ICML 2018
[arXiv]

Shampoo: Preconditioned Stochastic Tensor Optimization.
Vineet Gupta, Tomer Koren, Yoram Singer.
ICML 2018
[arXiv]

Multi-Armed Bandits with Metric Movement Costs.
Tomer Koren, Roi Livni, Yishay Mansour.
NIPS 2017

Affine-Invariant Online Optimization.
Tomer Koren, Roi Livni,
NIPS 2017

Bandits with Movement Costs and Adaptive Pricing.
Tomer Koren, Roi Livni, Yishay Mansour.
COLT 2017
[arXiv]

Tight Bounds for Bandit Combinatorial Optimization.
Alon Cohen, Tamir Hazan, Tomer Koren.
COLT 2017
[arXiv]

The Limits of Learning with Missing Data.
Brian Bullins, Elad Hazan, Tomer Koren.
NIPS 2016
[pdf]

Online Pricing With Strategic and Patient Buyers.
Michal Feldman, Tomer Koren, Roi Livni, Yishay Mansour, Aviv Zohar.
NIPS 2016
[pdf]

Online Learning with Feedback Graphs Without the Graphs.
Alon Cohen, Tamir Hazan, Tomer Koren.
ICML 2016
[arXiv]

Online Learning with Low Rank Experts.
Elad Hazan, Tomer Koren, Roi Livni, Yishay Mansour.
COLT 2016
[arXiv]

The Computational Power of Optimization in Online Learning.
Elad Hazan, Tomer Koren.
STOC 2016
[arXiv]

A Linear-Time Algorithm for Trust Region Problems.
Elad Hazan, Tomer Koren.
Mathematical Programming, 158(1-2): 363-381, 2016
[arXiv]

Fast Rates for Exp-concave Empirical Risk Minimization.
Tomer Koren, Kfir Levy.
NIPS 2015
[pdf]

Bandit Smooth Convex Optimization: Improving the Bias-Variance Tradeoff.
Ofer Dekel, Ronen Eldan, Tomer Koren.
NIPS 2015 (Spotlight)
[pdf] [full]

Bandit Convex Optimization: $\sqrt{T}$ Regret in One Dimension.
Sébastien Bubeck, Ofer Dekel, Tomer Koren, Yuval Peres.
COLT 2015
[arXiv]

Online Learning with Feedback Graphs: Beyond Bandits.
Noga Alon, Nicolò Cesa-Bianchi, Ofer Dekel, Tomer Koren.
COLT 2015
[arXiv]

Oracle-Based Robust Optimization via Online Learning.
Aharon Ben-Tal, Elad Hazan, Tomer Koren, Shie Mannor.
Operations Research, 63(3), 628-638, 2015
[arXiv]

The Blinded Bandit: Learning with Adaptive Feedback.
Ofer Dekel, Elad Hazan, Tomer Koren.
NIPS 2014
[pdf] [full]

Chasing Ghosts: Competing with Stateful Policies.
Uriel Feige, Tomer Koren, Moshe Tennenholtz.
FOCS 2014 (Invited to SICOMP)
[arXiv]

Logistic Regression: Tight Bounds for Stochastic and Online Optimization.
Elad Hazan, Tomer Koren, Kfir Levy.
COLT 2014
[arXiv]

Online Learning with Composite Loss Functions.
Ofer Dekel, Jian Ding, Tomer Koren, Yuval Peres.
COLT 2014
[arXiv]

Bandits with Switching Costs: $T^{2/3}$ Regret.
Ofer Dekel, Jian Ding, Tomer Koren, Yuval Peres.
STOC 2014
[arXiv]

Distributed Exploration in Multi-Armed Bandits.
Eshcar Hillel, Zohar Karnin, Tomer Koren, Ronny Lempel, Oren Somekh.
NIPS 2013 (Spotlight)
[arXiv]

Almost Optimal Exploration in Multi-Armed Bandits.
Zohar Karnin, Tomer Koren, Oren Somekh.
ICML 2013
[pdf]

Linear Regression with Limited Observation.
Elad Hazan, Tomer Koren.
ICML 2012 (Best Student Paper Runner-up)
[arXiv]

Supervised System Identification Based on Local PCA Models.
Tomer Koren, Ronen Talmon, Israel Cohen.
ICASSP 2012
[pdf]

Beating SGD: Learning SVMs in Sublinear Time.
Elad Hazan, Tomer Koren, Nathan Srebro.
NIPS 2011
[pdf] [full]


Other Publications

A Unified Approach to Adaptive Regularization in Online and Stochastic Optimization.
Vineet Gupta, Tomer Koren, Yoram Singer.
Manuscript
[arXiv]

Fast Stochastic Exp-Concave Optimization (Open Problem).
Tomer Koren
COLT 2013
[pdf]