Results 61 to 70 of about 3,057 (193)

Difference and the Liberation of Sufficient Reason

European Journal of Philosophy, EarlyView.
Abstract The Principle of Sufficient Reason (PSR) holds that every event and entity can be explained by a sufficient reason or cause. Philosophers have long struggled with the question of the PSR's compatibility with freedom, for if what occurs or exists follows necessarily from its sufficient reason then it seems it could not have been otherwise ...
Louis Matheou
wiley   +1 more source

Conformality on Semi-Riemannian Manifolds

Mediterranean Journal of Mathematics, 2015
The authors present an interesting study for a class \((C)\) of maps (conformal semi-Riemannian maps) between semi-Riemannian manifolds. The class \((C)\) contains semi-Riemannian submersions and isometric immersions. Some examples are given. A characterization is the following: Theorem 1.
Bejan, Cornelia-Livia, Eken, Semsi
openaire   +3 more sources

Two-Root Riemannian Manifolds

Mediterranean Journal of Mathematics, 2023
Osserman manifolds are a generalization of locally two-point homogeneous spaces. We introduce $k$-root manifolds in which the reduced Jacobi operator has exactly $k$ eigenvalues. We investigate one-root and two-root manifolds as another generalization of locally two-point homogeneous spaces. We prove that there is no two-root Riemannian manifold of odd
openaire   +2 more sources

Density‐Valued ARMA Models by Spline Mixtures

Journal of Time Series Analysis, EarlyView.
ABSTRACT This paper proposes a novel framework for modeling time series of probability density functions by extending autoregressive moving average (ARMA) models to density‐valued data. The method is based on a transformation approach, wherein each density function on a compact domain [0,1]d$$ {\left[0,1\right]}^d $$ is approximated by a B‐spline ...
Yasumasa Matsuda, Rei Iwafuchi
wiley   +1 more source

Conformality and Pseudo-Riemannian Manifolds.

MATHEMATICA SCANDINAVICA, 1971
Artykuł w: Annales Universitatis Mariae Curie-Skłodowska. Sectio A, Mathematica. Vol. 22/23/24 (1968/1969/1970), s. 113-123 ; streszcz. pol., ros. ; Artykuł w: Annales Universitatis Mariae Curie-Skłodowska. Sectio A, Mathematica. Vol. 22/23/24 (1968/1969/1970), s. 113-123 ; streszcz. pol., ros.
Ławrynowicz, Julian, Waliszewski, Włodzimierz (1934-2013)   +1 more
openaire   +3 more sources

How Should Bundle Theorists Account for Symmetrical Universes?

Noûs, EarlyView.
ABSTRACT Symmetrical universes, such as Max Black's famous “two‐sphere” world, are often taken to pose a serious challenge to the universal‐based bundle theory. In response, metaphysicians have either developed more sophisticated versions of the universal‐based account or simply converted to the trope‐based bundle theory.
Chiao‐Li Ou
wiley   +1 more source

Characterizing Affine Vector Fields on Pseudo-Riemannian Manifolds

Axioms
We study the characteristics of affine vector fields on pseudo-Riemannian manifolds and provide tensorial formulas that characterize these vector fields.
Norah Alshehri, Mohammed Guediri
doaj   +1 more source

The left-invariant contact metric structure on the Sol manifold

Учёные записки Казанского университета: Серия Физико-математические науки, 2020
Among the known eight-dimensional Thurston geometries, there is a geometry of the Sol manifold – a Lie group consisting of real special matrices. For a left-invariant Riemannian metric on the Sol manifold, the left shift group is a maximal simple ...
V.I. Pan’zhenskii, A.O. Rastrepina
doaj   +1 more source

On the Design of Model Predictive Setpoint Controllers for Nonholonomic Multibody Systems

Proceedings in Applied Mathematics and Mechanics, Volume 26, Issue 4, December 2026.
ABSTRACT Systems subject to constraints that are not integrable to position‐level constraints pose significant challenges for setpoint control. In particular, conventional linearization techniques may fail to yield controllable approximations, since certain directions of motion are only accessible through higher‐order interactions of the control inputs.
Mario Rosenfelder, Henrik Ebel, Peter Eberhard   +2 more
wiley   +1 more source

OSSERMAN LIGHTLIKE HYPERSURFACE CASES

Al-Ulum
In this study, we constructed four examples of light-like hypersurfaces that satisfy the conditions of an Osserman manifold, based on the characterisation of light-like hypersurfaces of a pseudo-Riemannian manifold of dimension m+2.
Paulin Shakwanda Mulebu, Oscar Lungiambudila Mamona, Gerard Tawaba Musian Ta-Yen, Alain Musesa Landa, Michael Kilela Makiese   +4 more
doaj   +1 more source