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Related papers: Passive States for Essential Observers

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In the setting of vector-valued quantum fields obeying a linear wave-equation in a globally hyperbolic, stationary spacetime, it is shown that the two-point functions of passive quantum states (mixtures of ground- or KMS-states) fulfill the…

Mathematical Physics · Physics 2009-10-31 Hanno Sahlmann , Rainer Verch

We study the limits to the localizability of events and reference frames in the $\kappa$-Minkowski quantum spacetime. Our main tool will be a representation of the $\kappa$-Minkowski commutation relations between coordinates, and the…

High Energy Physics - Theory · Physics 2019-04-17 Fedele Lizzi , Mattia Manfredonia , Flavio Mercati , Timothé Poulain

Meaningful topological invariants for mixed quantum states are challenging to identify as there is no unique way to define them, and most choices do not directly relate to physical observables. Here, we propose a simple pragmatic approach…

Quantum Gases · Physics 2017-12-13 Charles-Edouard Bardyn

We study state estimation for nonlinear differential-algebraic systems, where the nonlinearity satisfies a Lipschitz condition or a generalized monotonicity condition or a combination of these. The presented observer design unifies earlier…

Optimization and Control · Mathematics 2019-10-10 Thomas Berger , Lukas Lanza

We resolve the long standing question of temperature dependence of uniformly moving bodies by means of a quantum statistical treatment centred on the zeroth law of thermodynamics. The key to our treatment is the result, established by…

Mathematical Physics · Physics 2015-05-13 Geoffrey L. Sewell

This paper completes a previous work by constructing a class of positive-energy relativistic spatial localization observables in Minkowski spacetime within quantum field theory, using the stress-energy-momentum tensor smeared with suitable…

Mathematical Physics · Physics 2026-04-08 Valter Moretti

In this paper we propose a new state observer design technique for nonlinear systems. It consists of an extension of the recently introduced parameter estimation-based observer, which is applicable for systems verifying a particular…

Dynamical Systems · Mathematics 2020-11-16 Romeo Ortega , Alexey Bobtsov , Nikolay Nikolaev , Johannes Schiffer , Denis Dochain

We introduce a subclass of Lie symmetries, called parameter-state symmetries, to analyse the local structural identifiability and observability of mechanistic models consisting of state-dependent ODEs with observed outputs. These symmetries…

Dynamical Systems · Mathematics 2026-03-13 Johannes G. Borgqvist , Alexander P. Browning , Fredrik Ohlsson , Ruth E. Baker

We describe an algebra of observables for a static patch in de Sitter space, with operators gravitationally dressed to the worldline of an observer. The algebra is a von Neumann algebra of Type II$_1$. There is a natural notion of entropy…

High Energy Physics - Theory · Physics 2023-07-04 Venkatesa Chandrasekaran , Roberto Longo , Geoff Penington , Edward Witten

We adapt the axioms of the quantum mechanics to the quantum Minkowski space-time coordinates and their transformations under the quantum Lorentz group to show how we can formulate the noncommutative special relativity and its quantum…

Mathematical Physics · Physics 2007-05-23 M. Lagraa

The issue of single range based observability analysis and observer design for the kinematics model of a 3D vehicle subject to a constant unknown drift velocity is addressed. The proposed method departs from alternative solutions to the…

Robotics · Computer Science 2014-09-02 Giovanni Indiveri , Gianfranco Parlangeli

We attempt to prove the existence of Reeh-Schlieder states on curved spacetimes in the framework of locally covariant quantum field theory using the idea of spacetime deformation and assuming the existence of a Reeh-Schlieder state on a…

Mathematical Physics · Physics 2009-04-17 Ko Sanders

This paper introduces a new nonlinear observer for state estimation of linear time invariant systems. The proposed observer contains a (nonlinear) cubic term in its error dynamics. "For the final version of this article, please refer to the…

Optimization and Control · Mathematics 2020-06-05 Mohammad Mahdi Share Pasand

This paper considers the design of nonlinear observers for invariant systems posed on finite-dimensional connected Lie groups with measurements generated by a transitive group action on an associated homogeneous space. We consider the case…

Optimization and Control · Mathematics 2008-10-07 C. Lageman , J. Trumpf , R. Mahony

To any periodic, unital and full C*-dynamical system (A, \alpha, R) an invertible operator s acting on the Banach space of trace functionals of the fixed point algebra is canonically associated. KMS states correspond to positive…

Operator Algebras · Mathematics 2009-10-31 C. Pinzari , Y. Watatani , K. Yonetani

This work proposes a detectability condition for linear time-varying systems based on the exponential dichotomy spectrum. The condition guarantees the existence of an observer, whose gain is determined only by the unstable modes of the…

Systems and Control · Electrical Eng. & Systems 2022-09-20 Markus Tranninger , Richard Seeber , Martin Steinberger , Martin Horn , Christian Pötzsche

This paper revisits the previously proposed linear asymptotic observer of the motion state variables with nonlinear friction and provides a robust design suitable for both, transient presliding and steady-state sliding phases of the…

Systems and Control · Electrical Eng. & Systems 2023-05-26 Michael Ruderman

Relying on recent research results on Neural ODEs, this paper presents a methodology for the design of state observers for nonlinear systems based on Neural ODEs, learning Luenberger-like observers and their nonlinear extension…

Systems and Control · Electrical Eng. & Systems 2023-05-18 Keyan Miao , Konstantinos Gatsis

Recently it has been shown that the Reeh-Schlieder property w.r.t. thermal equilibrium states is a direct consequence of locality, additivity and the relativistic KMS condition. Here we extend this result to ground states.

High Energy Physics - Theory · Physics 2009-10-31 Christian Jaekel

This paper deals with the state estimation of linear time-invariant systems using distributed observers with local sampled-data measurement and aperiodic communication. Each observer agent perceives partial information of the system to be…

Systems and Control · Electrical Eng. & Systems 2024-06-11 Shimin Wang , Ya-Jun Pan , Martin Guay