Observer with a constant proper acceleration

Halting eternal acceleration with an effective negative cosmological constant

In order to solve the problem of eternal acceleration, a model has been recently proposed including both a negative cosmological constant Λ and a scalar field evolving under the action of an exponential potential. We further explore this model by contrasting it against the Hubble diagram of Type Ia supernovae, the gas mass fraction in galaxy clusters and the acoustic peak and shift parameters. ...

A Class of Series Acceleration Formulae for Catalan’s Constant

Abstract. In this note, we develop transformation formulae and expansions for the log tangent integral, which are then used to derive series acceleration formulae for certain values of Dirichlet L-functions, such as Catalan’s constant. The formulae are characterized by the presence of an infinite series whose general term consists of a linear recurrence damped by the central binomial coefficien...

A finite-time convergent observer with robustness to piecewise-constant measurement noise

Motivated by the design of observers with good performance and robustness to measurement noise, the problem of estimating the state of a linear time-invariant system in finite time and robustly with respect to measurement noise is considered. Using a hybrid systems framework, a hybrid observer producing an estimate that converges to the plant state in finite time, even under unknown piecewise-c...

Hypersurfaces with Constant Mean Curvature in a Lorentzian Space Form

A Novel Qualitative State Observer

The state estimation of a quantized system (Q.S.) is a challenging problem for designing feedback control and model-based fault diagnosis algorithms. The core of a Q.S. is a continuous variable system whose inputs and outputs are represented by their corresponding quantized values. This paper concerns with state estimation of a Q.S. by a qualitative observer. The presented observer in this pape...