Christoph Spiegel

about me

I am part of Sebastian Pokutta's IOL lab, deputy head of the AIS2T department at ZIB, and a postdoc representative member of the MATH+ Board.

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.
The 4-color Ramsey Multiplicity of Triangles
Proceedings of Discrete Mathematics Days, 2024. [URL] [arXiv] [code]
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]
Kiem, A., Pokutta, S., and Spiegel, C.
Categorification of Flag Algebras
Proceedings of Discrete Mathematics Days, 2024. [URL]
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.
How I Learned to Stop Worrying and Love Retraining
Proceedings of International Conference on Learning Representations, 2023. [URL] [arXiv] [code]

Kiem, A., Pokutta, S., and Spiegel, C.
The 4-color Ramsey Multiplicity of Triangles
Proceedings of Discrete Mathematics Days, 2024. [URL] [arXiv] [code]
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]
Kiem, A., Pokutta, S., and Spiegel, C.
Categorification of Flag Algebras
Proceedings of Discrete Mathematics Days, 2024. [URL]
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.
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.
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]
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

Parczyk, O., Pokutta, S., Spiegel, C., and Szabó, T.
New Ramsey Multiplicity Bounds and Search Heuristics
Foundations of Computational Mathematics, 2024. [DOI] [arXiv] [code]
Mundinger, K., Pokutta, S., Spiegel, C., and Zimmer, M.
Extending the Continuum of Six-Colorings
Geombinatorics Quarterly, XXXIV, 2024. [URL] [arXiv]
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]

Parczyk, O., Pokutta, S., Spiegel, C., and Szabó, T.
New Ramsey Multiplicity Bounds and Search Heuristics
Foundations of Computational Mathematics, 2024. [DOI] [arXiv] [code]
Mundinger, K., Pokutta, S., Spiegel, C., and Zimmer, M.
Extending the Continuum of Six-Colorings
Geombinatorics Quarterly, XXXIV, 2024. [URL] [arXiv]
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]
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]
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]
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]