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200 papers

In control theory, researchers need to understand a system's local and global behaviors in relation to its initial conditions. When discussing observability, the main focus is on the ability to analyze the system using an output space…

Optimization and Control · Mathematics 2025-03-26 Thiago Matheus Cavalheiro , Alexandre José Santana , Victor Ayala

We prove the uniqueness of high cofinality limit models in stable abstract elementary classes (AECs) with amalgamation, assuming the existence of a rather weak independence relation. $\textbf{Theorem.}$ Suppose $\mathbf{K}$ is a…

Logic · Mathematics 2025-11-25 Jeremy Beard

We try to build, provably in ZFC, for a first order T a model in which any isomorphism between two Boolean algebras is definable. The problem, compared to [Sh:384], is with pseudo-finite Boolean algebras. A side benefit is that we do not…

Logic · Mathematics 2016-01-15 Saharon Shelah

This paper investigates the controllability of finite-dimensional linear fractional systems involving an uncertain parameter. We establish new results on the simultaneous and average controllability. In particular, we show that average…

Optimization and Control · Mathematics 2025-08-05 Idriss Boutaayamou , Fouad Et-Tahri , Lahcen Maniar

We continue our investigation =of Shelah's interpretability orders $\trianglelefteq^*_\kappa$ as well as the new orders $\trianglelefteq^\times_\kappa$. In particular, we give streamlined proofs of the existence of minimal unstable,…

Logic · Mathematics 2018-11-14 Douglas Ulrich

The manuscript is concerned with the Rudin-Keisler order of ultrafilters on measurable cardinals. The main theorem proved read as follows: Given regular cardinals $\lambda\leq \kappa$, the following theories are equiconsistent modulo ZFC:…

Logic · Mathematics 2026-01-16 Yair Hayut , Alejandro Poveda

Suppose L is a relational language and P in L is a unary predicate. If M is an L-structure then P(M) is the L-structure formed as the substructure of M with domain {a: M models P(a)}. Now suppose T is a complete first order theory in L with…

Logic · Mathematics 2008-02-03 Bradd Hart , Saharon Shelah

There is a strong interest in optimal manipulating of quantum systems by external controls. Traps are controls which are optimal only locally but not globally. If they exist, they can be serious obstacles to the search of globally optimal…

Quantum Physics · Physics 2015-09-03 Alexander Pechen , Nikolay Il'in

Linear systems on Lie groups are a natural generalization of linear system on Euclidian spaces. For such systems, this paper studies controllability by taking in consideration the eigenvalues of an associated derivation D. When the state…

Optimization and Control · Mathematics 2016-01-05 Adriano Da Silva

Advanced control in Lambda ($\Lambda$) scheme of a solid state architecture of artificial atoms and quantized modes would allow the translation to the solid-state realm of a whole class of phenomena from quantum optics, thus exploiting new…

Quantum Physics · Physics 2019-08-19 G. Falci , P. G. Di Stefano , A. Ridolfo , A. D'Arrigo , G. S. Paraoanu , E. Paladino

We establish a relationship between a certain notion of covering complexity of a Riemannian spin manifold and positive lower bounds on its scalar curvature. This makes use of a pairing between quantitative operator $K$-theory and Lipschitz…

K-Theory and Homology · Mathematics 2024-09-02 Hao Guo , Guoliang Yu

This paper examines and strengthens the Cuntz-Thomsen picture of equivariant Kasparov theory for arbitrary second-countable locally compact groups, in which elements are given by certain pairs of cocycle representations between C*-dynamical…

Operator Algebras · Mathematics 2025-03-25 James Gabe , Gábor Szabó

Supramenability of groups is characterised in terms of invariant measures on locally compact spaces. This opens the door to constructing interesting crossed product C*-algebras for non-supramenable groups. In particular, stable Kirchberg…

Operator Algebras · Mathematics 2013-12-09 Julian Kellerhals , Nicolas Monod , Mikael Rordam

Let H be a pseudovariety of groups in which the kappa-word problem is decidable. Here, kappa denotes the canonical implicit signature, which consists of the multiplication and the (omega-1)-power. We prove that the kappa-word problem is…

Group Theory · Mathematics 2015-12-04 Célia Borlido

In this paper, we study the control of a class of time-invariant linear ensemble systems whose natural dynamics are linear in the system parameter. This class of ensemble control systems arises from practical engineering and physical…

Optimization and Control · Mathematics 2014-10-07 Jr-Shin Li , Ji Qi

A compactness theorem is proved for a family of K\"{a}hler surfaces with constant scalar curvature and volume bounded from below, diameter bounded from above, Ricci curvature bounded and the signature bounded from below. Furthermore, a…

Differential Geometry · Mathematics 2013-04-04 Hongliang Shao

We consider affine control systems with two scalar controls, such that one control vector field vanishes at an equilibrium state. We state two necessary conditions of local controllability around this equilibrium, involving the iterated Lie…

Optimization and Control · Mathematics 2024-03-05 Laetitia Giraldi , Pierre Lissy , Clément Moreau , Jean-Baptiste Pomet

Answering a question by Honsell and Plotkin, we show that there are two equations between lambda terms, the so-called subtractive equations, consistent with lambda calculus but not simultaneously satisfied in any partially ordered model…

Logic in Computer Science · Computer Science 2015-07-01 Antonino Salibra , Alberto Carraro

In a recent paper, a realizability technique has been used to give a semantics of a quantum lambda calculus. Such a technique gives rise to an infinite number of valid typing rules, without giving preference to any subset of those. In this…

Logic in Computer Science · Computer Science 2023-06-22 Alejandro Díaz-Caro , Octavio Malherbe

We prove a squeezing/stability theorem for delta-epsilon controlled L-groups when the control map is a fibration on a finite polyhedron. A relation with boundedly-controlled L-groups is also discussed.

Geometric Topology · Mathematics 2009-03-18 Erik K. Pedersen , Masayuki Yamasaki