40 citations · 250 across the 28 of their papers we have counts for
9 papers · 1 filter
A variation principle for ground spaces
Stephan Weis
The ground spaces of a vector space of hermitian matrices, partially ordered by inclusion, form a lattice constructible from top to bottom in terms of intersections of maximal grou…
A new signature of quantum phase transitions from the numerical range
Ilya M. Spitkovsky, Stephan Weis
The ground state energy of a finite-dimensional one-parameter Hamiltonian and the continuity of a maximum-entropy inference map are discussed in the context of quantum critical phe…
Continuity of the maximum-entropy inference: Convex geometry and numerical ranges approach
Leiba Rodman, Ilya M. Spitkovsky, Arleta Szkoła +1
We study the continuity of an abstract generalization of the maximum-entropy inference - a maximizer. It is defined as a right-inverse of a linear map restricted to a convex body w…
Maximum-entropy inference and inverse continuity of the numerical range
Stephan Weis
We study the continuity of the maximum-entropy inference map for two observables in finite dimensions. We prove that the continuity is equivalent to the strong continuity of the se…
Maximizing the divergence from a hierarchical model of quantum states
Stephan Weis, Andreas Knauf, Nihat Ay +1
We study many-party correlations quantified in terms of the Umegaki relative entropy (divergence) from a Gibbs family known as a hierarchical model. We derive these quantities from…
Quantum Convex Support
Stephan Weis
Convex support, the mean values of a set of random variables, is central in information theory and statistics. Equally central in quantum information theory are mean values of a se…
Entropy Distance: New Quantum Phenomena
Andreas Knauf, Stephan Weis
We study a curve of Gibbsian families of complex 3x3-matrices and point out new features, absent in commutative finite-dimensional algebras: a discontinuous maximum-entropy inferen…
Polyhedral Voronoi Cells
Ina Voigt, Stephan Weis
Voronoi cells of a discrete set in Euclidean space are known as generalized polyhedra. We identify polyhedral cells of a discrete set through a direction cone. For an arbitrary set…
Information topologies on non-commutative state spaces
Stephan Weis
We define an information topology (I-topology) and a reverse information topology (rI-topology) on the state space of a C*-subalgebra of Mat(n,C). These topologies arise from seque…