Preprints

• S. Weis,
Matrix systems, algebras, and open maps.
◦ arXiv

• A. S. Arora, J. Roland, C. Vlachou, and S. Weis,
Protocols for quantum weak coin flipping.
◦ arXiv


Refereed Journal Papers

20) S. Weis,
A note on faces of convex sets,
Journal of Convex Analysis 32:3, 901–919 (2025).
◦ Special issue dedicated to R. Tyrrell Rockafellar on his 90th birthday ◦ arXiv

19) S. Weis and J. Gouveia,
The face lattice of the set of reduced density matrices and its coatoms,
Information Geometry 6:1, 293-326 (2023).
◦ free reading on the journal website! ◦ arXiv

18) D. Plaumann, R. Sinn, and S. Weis,
Kippenhahn's theorem for joint numerical ranges and quantum states,
SIAM Journal on Applied Algebra and Geometry 5:1, 86-113 (2021).
◦ arXiv ◦ Q1 (Scopus)

17) S. Weis and M. E. Shirokov,
The face generated by a point, generalized affine constraints, and quantum theory,
Journal of Convex Analysis 28:3, 847-870 (2021).
◦ arXiv

16) S. W. Weis and M. E. Shirokov,
Extreme points of the set of quantum states with bounded energy,
Russian Mathematical Surveys 76:1, 190-192 (2021).
◦ open access on the journal website! ◦ arXiv ◦ Q1 (Scopus)

15) S. Weis,
A variational principle for ground spaces,
Reports on Mathematical Physics 82:3, 317-336 (2018).
◦ arXiv

14) I. M. Spitkovsky and S. Weis,
Signatures of quantum phase transitions from the numerical range,
Journal of Mathematical Physics 59:12, 121901 (2018).
◦ arXiv

13) K. Szymański, S. Weis, and K. Życzkowski,
Classification of joint numerical ranges of three hermitian matrices of size three,
Linear Algebra and its Applications 545, 148-173 (2018).
◦ open access on the journal website! ◦ arXiv ◦ Q1 (Scopus)

12) S. Weis,
Operator systems and convex sets with many normal cones,
Journal of Convex Analysis 25:1, 41-64 (2018).
◦ arXiv

11) I. M. Spitkovsky and S. Weis,
Pre-images of extreme points of the numerical range, and applications,
Operators and Matrices 10:4, 1043-1058 (2016).
◦ special issue in memory of Leiba Rodman ◦ arXiv

10) S. Weis,
Maximum-entropy inference and inverse continuity of the numerical range,
Reports on Mathematical Physics 77:2, 251-263 (2016).
◦ arXiv

9) L. Rodman, I. M. Spitkovsky, A. Szkoła, and S. Weis,
Continuity of the maximum-entropy inference: Convex geometry and numerical ranges approach,
Journal of Mathematical Physics 57:1, 015204 (2016).
◦ special issue: Operator Algebras and Quantum Information Theory ◦ arXiv

8) S. Weis, A. Knauf, N. Ay, and M.-J. Zhao,
Maximizing the divergence from a hierarchical model of quantum states,
Open Systems & Information Dynamics 22:1, 1550006 (2015).
◦ arXiv ◦ SFI Working Paper

7) S. Weis,
Continuity of the maximum-entropy inference,
Communications in Mathematical Physics 330:3, 1263-1292 (2014).
◦ arXiv ◦ MiS Preprint Repository ◦ Q1 (Scopus)

6) S. Weis,
Information topologies on non-commutative state spaces,
Journal of Convex Analysis 21:2, 339-399 (2014).
◦ open access on the journal website! ◦ arXiv ◦ MiS Preprint Repository ◦ Q1 (Scopus)

5) S. Weis and A. Knauf,
Entropy distance: New quantum phenomena,
Journal of Mathematical Physics 53:10, 102206 (2012).
◦ arXiv ◦ MiS Preprint Repository

4) S. Weis,
Duality of non-exposed faces,
Journal of Convex Analysis 19:3, 815-835 (2012).
◦ open access on the journal website! ◦ arXiv ◦ MiS Preprint Repository ◦ Q1 (Scopus)

3) S. Weis,
A note on touching cones and faces,
Journal of Convex Analysis 19:2, 323-353 (2012).
◦ open access on the journal website! ◦ arXiv ◦ Q1 (Scopus)

2) S. Weis,
Quantum convex support,
Linear Algebra and its Applications 435:12, 3168-3188 (2011).
◦ open access on the journal website! ◦ arXiv

1) I. Voigt and S. Weis,
Polyhedral Voronoi cells,
Contributions to Algebra and Geometry 51:2, 587-598 (2010).
◦ open access on the journal website! ◦ arXiv


Refereed Conference Papers

5) S. Weis,
Kippenhahn's construction revisited,
in: M. Ptak, et al. (eds.), Operator and Matrix Theory, Function Spaces, and Applications,
IWOTA 2022, Operator Theory: Advances and Applications 295, Cham: Birkhäuser, 2024, 385-396.
◦ arXiv

4) A. S. Arora, J. Roland, and S. Weis,
Quantum weak coin flipping,
STOC 2019: Proceedings of the Annual ACM Symposium on Theory of Computing, 2019, 205-216.
◦ PDF file (914kB) ◦ arXiv

3) S. Weis,
The MaxEnt extension of a quantum Gibbs family, convex geometry and geodesics,
in: A. Mohammad-Djafari, and F. Barbaresco, (eds.), Bayesian Inference and Maximum Entropy Methods in Science and Engineering (MaxEnt 2014),
AIP Conference Proceedings 1641, 173-180 (2015).
◦ arXiv

2) S. Weis,
Discontinuities in the maximum-entropy inference,
in: U. von Toussaint (ed.), Bayesian Inference and Maximum Entropy Methods in Science and Engineering (MaxEnt 2012),
AIP Conference Proceedings 1553, 192-199 (2013).
◦ arXiv

1) I. Bengtsson, S. Weis, and K. Życzkowski,
Geometry of the set of mixed quantum states: An apophatic approach,
in: P. Kielanowski, et al. (eds.),
Geometric Methods in Physics, Basel: Birkhäuser, 2013, 175-197.
◦ arXiv ◦ MiS Preprint Repository


Academic Theses

3) S. Weis,
Exponential Families with Incompatible Statistics and Their Entropy Distance,
Doctoral Thesis, Erlangen, Germany, 2010.

2) S. Weis,
Invariants for the Ideal Boundary of a Tree,
Diploma Thesis, Erlangen, Germany, 2004.
◦ PDF file (639kB)

1) S. Weis,
Dynamics on Graphs,
Master Thesis, Bristol, UK, 2004.
◦ PDF file (955kB)


Unpublished Manuscripts

3) A. S. Arora, J. Roland, C. Vlachou, and S. Weis,
Solutions to quantum weak coin flipping, 2022.
◦ Cryptology ePrint Archive

2) S. Weis,
Decomposition of symmetric separable states and ground state energy of bosonic systems, 2020.
◦ arXiv

1) S. Weis,
On a theorem by Kippenhahn, 2017.
◦ arXiv

Slides and Videos

6) Choquet's Theorem for Constrained Sets of Quantum States, talk at the special session "Generalized Numerical Ranges, Operator Theory, and Quantum Information" at the 33rd IWOTA, Krakow, Poland, September 2022, slides (PDF, 564kB)

Video of a similar, longer talk at the MIAN online seminar "Quantum Probability, Statistics, Information", Steklov Mathematical Institute, Moscow, Russia, March 2021

5) Analysis of Generalized Gibbs States, talk at the conference Entropy 2021: The Scientific Tool of the 21st Century, Porto, Portugal, May 2021, slides (PDF, 1.1MB)

4) Quantum Weak Coin Flipping, talk at the SUMA 2019 - Reunión anual de la UMA junto a la SOMACHI, Mendoza, Argentina, September 2019, slides (PDF, 147kB)

3) Classification of joint numerical ranges of three hermitian matrices of size three, talk at The Fourteenth Workshop on Numerical Ranges and Numerical Radii, Munich, Germany, June 2018, slides (PDF, 1.8MB)

2) A new signature of quantum phase transitions from the numerical range, talk at the conference Entropy 2018: From Physics to Information Sciences and Geometry, University of Barcelona, Spain, May 2018, slides (PDF, 268kB)

1) Stability of the set of quantum states, talk at the Workshop "Probabilistic techniques and Quantum Information Theory" at the Trimester "Analysis in Quantum Information Theory", Institut Henri Poincaré, Paris, France, October 2017, video

Slides (PDF, 2.1MB) from a similar talk at the Pure Mathematics Research Centre, Queen's University Belfast, UK, November 2017

Posters

2) The rI-Closure of an Exponential Family and Ground Spaces, poster presented at the Conference «Quantum Information Theory» at the Trimester «Analysis in Quantum Information Theory», Institut Henri Poincaré, Paris, France, December 2017, poster (PDF, 863kB)

1) Mysterious Discontinuity of Quantum Correlation, poster presented at the Joint IAS-ICTP School on Quantum Information Processing, Nanyang Executive Centre, Nanyang Technological University, Singapore, January 2016, poster (PDF, 535kB)

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