Christoph Spiegel

about me

I am part of Sebastian Pokutta's IOL lab, deputy head of the AIS2T department at ZIB, and a member of MATH+. I also lead the seven person iol.COMP group and am co-PI of two MATH+ projects, each funding a PhD position. Click here if you are interested in joining.

I defended my PhD in additive and probabilistic combinatorics in 2020 at UPC Barcelona under Juanjo Rué and Oriol Serra and currently work on combinatorics, optimization, and learning. In particular, I like using optimization and AI tools for theoretical maths [1] [2] [3], flag algebras [4] [5] [6], and formal proof verification [7]. Click here for a complete list of my publications.

I teach most semesters at either TUB or FUB, usually on discrete mathematics. My next course is on formal proof verification with Lean. Click here for a complete list of courses.

I maintain both the Berlin Math Seminars page and the Formal Proofs from THE BOOK blog.

proceedings

Kiem, A., Pokutta, S., and Spiegel, C.
Categorification of Flag Algebras
Proceedings of Discrete Mathematics Days, 2024. [URL]
Kiem, A., Pokutta, S., and Spiegel, C.
The 4-color Ramsey Multiplicity of Triangles
Proceedings of Discrete Mathematics Days, 2024. [URL] [arXiv] [code]
Mundinger, K., Pokutta, S., Spiegel, C., and Zimmer, M.
Extending the Continuum of Six-Colorings
Proceedings of Discrete Mathematics Days, 2024. [URL] [arXiv]
Zimmer, M., Spiegel, C., and Pokutta, S.
Sparse Model Soups: A Recipe for Improved Pruning Via Model Averaging
Proceedings of International Conference on Learning Representations, 2024. [URL] [arXiv]
Parczyk, O., Pokutta, S., Spiegel, C., and Szabó, T.
Fully Computer-assisted Proofs in Extremal Combinatorics
Proceedings of AAAI Conference on Artificial Intelligence, 2023. [DOI] [URL] [arXiv] [code]

Kiem, A., Pokutta, S., and Spiegel, C.
Categorification of Flag Algebras
Proceedings of Discrete Mathematics Days, 2024. [URL]
Kiem, A., Pokutta, S., and Spiegel, C.
The 4-color Ramsey Multiplicity of Triangles
Proceedings of Discrete Mathematics Days, 2024. [URL] [arXiv] [code]
Mundinger, K., Pokutta, S., Spiegel, C., and Zimmer, M.
Extending the Continuum of Six-Colorings
Proceedings of Discrete Mathematics Days, 2024. [URL] [arXiv]
Zimmer, M., Spiegel, C., and Pokutta, S.
Sparse Model Soups: A Recipe for Improved Pruning Via Model Averaging
Proceedings of International Conference on Learning Representations, 2024. [URL] [arXiv]
Parczyk, O., Pokutta, S., Spiegel, C., and Szabó, T.
Fully Computer-assisted Proofs in Extremal Combinatorics
Proceedings of AAAI Conference on Artificial Intelligence, 2023. [DOI] [URL] [arXiv] [code]
Rué, J. J., and Spiegel, C.
The Rado Multiplicity Problem in Vector Spaces Over Finite Fields
Proceedings of European Conference on Combinatorics, 2023. [DOI] [URL] [arXiv] [code]
Zimmer, M., Spiegel, C., and Pokutta, S.
How I Learned to Stop Worrying and Love Retraining
Proceedings of International Conference on Learning Representations, 2023. [URL] [arXiv] [code]
Parczyk, O., Pokutta, S., Spiegel, C., and Szabó, T.
New Ramsey Multiplicity Bounds and Search Heuristics
Proceedings of Discrete Mathematics Days, 2022. [arXiv] [code]
Rué, J. J., and Spiegel, C.
On a Problem of Sárközy and Sós for Multivariate Linear Forms
Proceedings of Discrete Mathematics Days, 2018. [URL] [arXiv]
Kusch, C., Rué, J. J., Spiegel, C., and Szabó, T.
Random Strategies Are Nearly Optimal for Generalized Van Der Waerden Games
Proceedings of European Conference on Combinatorics, 2017. [URL] [arXiv]

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journal

Mundinger, K., Pokutta, S., Spiegel, C., and Zimmer, M.
Extending the Continuum of Six-Colorings
Geombinatorics Quarterly, XXXIV, 2024. [URL] [arXiv]
Parczyk, O., Pokutta, S., Spiegel, C., and Szabó, T.
New Ramsey Multiplicity Bounds and Search Heuristics
Foundations of Computational Mathematics, 2024. [DOI] [arXiv] [code]
Kamčev, N., and Spiegel, C.
Another Note on Intervals in the Hales-Jewett Theorem
Electronic Journal of Combinatorics, 29(1), 2022. [DOI] [URL] [arXiv]
Cao-Labora, G., Rué, J. J., and Spiegel, C.
An Erdős-Fuchs Theorem for Ordered Representation Functions
Ramanujan Journal, 56, 183–2091, 2021-10. [DOI] [URL] [arXiv]
Fabian, D., Rué, J. J., and Spiegel, C.
On Strong Infinite Sidon and Bₕ Sets and Random Sets of Integers
Journal of Combinatorial Theory, Series A, 182, 2021-08. [DOI] [URL] [arXiv]

Mundinger, K., Pokutta, S., Spiegel, C., and Zimmer, M.
Extending the Continuum of Six-Colorings
Geombinatorics Quarterly, XXXIV, 2024. [URL] [arXiv]
Parczyk, O., Pokutta, S., Spiegel, C., and Szabó, T.
New Ramsey Multiplicity Bounds and Search Heuristics
Foundations of Computational Mathematics, 2024. [DOI] [arXiv] [code]
Kamčev, N., and Spiegel, C.
Another Note on Intervals in the Hales-Jewett Theorem
Electronic Journal of Combinatorics, 29(1), 2022. [DOI] [URL] [arXiv]
Cao-Labora, G., Rué, J. J., and Spiegel, C.
An Erdős-Fuchs Theorem for Ordered Representation Functions
Ramanujan Journal, 56, 183–2091, 2021-10. [DOI] [URL] [arXiv]
Fabian, D., Rué, J. J., and Spiegel, C.
On Strong Infinite Sidon and Bₕ Sets and Random Sets of Integers
Journal of Combinatorial Theory, Series A, 182, 2021-08. [DOI] [URL] [arXiv]
Corsten, J., Mond, A., Pokrovskiy, A., Spiegel, C., and Szabó, T.
On the Odd Cycle Game and Connected Rules
European Journal of Combinatorics, 89, 2020-10. [DOI] [URL] [arXiv]
Candela, P., Serra, O., and Spiegel, C.
A Step Beyond Freĭman’s Theorem for Set Addition Modulo a Prime
Journal De Théorie Des Nombres De Bordeaux, 32(1), 275–289, 2020. [DOI] [URL] [arXiv]
Rué, J. J., and Spiegel, C.
On a Problem of Sárközy and Sós for Multivariate Linear Forms
Revista Matemática Iberoamericana, 36(7), 2107–2119, 2020. [DOI] [URL] [arXiv]
Kusch, C., Rué, J. J., Spiegel, C., and Szabó, T.
On the Optimality of the Uniform Random Strategy
Random Structures & Algorithms, 55(2), 371–401, 2019-09. [DOI] [URL] [arXiv]
Freĭman, G. A., Serra, O., and Spiegel, C.
Additive Volume of Sets Contained in Few Arithmetic Progressions
INTEGERS, 19, 2019. [URL] [arXiv]
Rué, J. J., Spiegel, C., and Zumalacárregui, A.
Threshold Functions and Poisson Convergence for Systems of Equations in Random Sets
Mathematische Zeitschrift, 288, 333–360, 2018. [DOI] [URL] [arXiv]
Spiegel, C.
A Note on Sparse Supersaturation and Extremal Results for Linear Homogeneous Systems
Electronic Journal of Combinatorics, 24(3), 2017. [DOI] [URL] [arXiv]

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preprint

Zimmer, M., Andoni, M., Spiegel, C., and Pokutta, S.
PERP: Rethinking the Prune-Retrain Paradigm in the Era of LLMs
[arXiv] [code]
Zimmer, M., Spiegel, C., and Pokutta, S.
Compression-aware Training of Neural Networks Using Frank-Wolfe
[arXiv]
Combettes, C., Spiegel, C., and Pokutta, S.
Projection-free Adaptive Gradients for Large-scale Optimization
[arXiv] [summary] [code]
Pokutta, S., Spiegel, C., and Zimmer, M.
Deep Neural Network Training with Frank-Wolfe
[arXiv] [summary] [code]
Salia, N., Spiegel, C., Tompkins, C., and Zamora, O.
Independent Chains in Acyclic Posets
[arXiv]