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Related papers: Two roads to noncommutative causality

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Using the bicomplex approach we discuss a noncommutative system in two--dimensional Euclidean space. It is described by an equation of motion which reduces to the ordinary sine--Gordon equation when the noncommutation parameter is removed,…

High Energy Physics - Theory · Physics 2007-05-23 Marcus T. Grisaru , Silvia Penati

The magnetic backgrounds that physically give rise to spacetime noncommutativity are generally treated using noncommutative geometry. In this article we prove that also the theory of generalised complex manifolds contains the necessary…

High Energy Physics - Theory · Physics 2009-11-11 J. M. Isidro

Causal inference is central to statistics and scientific discovery, enabling researchers to identify cause-and-effect relationships beyond associations. While traditionally studied within Euclidean spaces, contemporary applications…

Methodology · Statistics 2025-07-01 Satarupa Bhattacharjee , Bing Li , Xiao Wu , Lingzhou Xue

In this paper we present an invariant formulation of special relativity, i.e., the ''true transformations relativity.'' It deals either with true tensor quantities (when no basis has been introduced) or equivalently with coordinate- based…

General Physics · Physics 2007-05-23 Tomislav Ivezic

I recall the main motivation to study quantum field theories on noncommutative spaces and comment on the most-studied example, the noncommutative R^4. That algebra is given by the *-product which can be written in (at least) two ways: in an…

High Energy Physics - Theory · Physics 2007-05-23 Raimar Wulkenhaar

We define and study a new kind of relation between two diffeomorphic Lorentzian manifolds called {\em causal relation}, which is any diffeomorphism characterized by mapping every causal vector of the first manifold onto a causal vector of…

General Relativity and Quantum Cosmology · Physics 2016-08-16 Alfonso García-Parrado , José M M Senovilla

Alain Connes' noncommutative theory led to an interesting model including both Standard Model of particle physics and Euclidean Gravity. Nevertheless, an hyperbolic version of the gravitational part would be necessary to make physical…

Mathematical Physics · Physics 2013-06-11 Nicolas Franco

Any counterexample to the two-dimensional Jacobian Conjecture gives a rational map from one projective plane to another. We use some ideas of the Minimal Model Program to study the combinatorial structure of a rational surface, that is…

Algebraic Geometry · Mathematics 2009-12-25 Alexander Borisov

We consider the usual causal structure $(I^+,J^+)$ on a spacetime, and a number of alternatives based on Minguzzi's $D^+$ and Sorkin and Woolgar's $K^+$, in the case where the spacetime metric is continuous, but not necessarily smooth. We…

General Relativity and Quantum Cosmology · Physics 2021-06-30 Leonardo García-Heveling

We consider planar noncommutative theories such that the coordinates verify a space-dependent commutation relation. We show that, in some special cases, new coordinates may be introduced that have a constant commutator, and as a consequence…

High Energy Physics - Theory · Physics 2008-11-26 D. H. Correa , C. D. Fosco , F. A. Schaposnik , G. Torroba

We give a broad overview of a construction of a theory for matter on fixed causal set backgrounds. We introduce the Sorkin-Johnston formalism for a free (real) scalar field theory that is applicable to regions of continuum spacetimes as…

High Energy Physics - Theory · Physics 2023-06-09 Nomaan X

We study the formulation of quantum statistical mechanics in noncommutative spaces. We construct microcanonical and canonical ensemble theory in noncommutative spaces. We consider for illustration some basic and important examples in the…

High Energy Physics - Theory · Physics 2009-06-10 S. A. Alavi

Quantum mechanics in a noncommutative plane is considered. For a general two dimensional central field, we find that the theory can be perturbatively solved for large values of the noncommutative parameter ($\theta$) and explicit…

High Energy Physics - Theory · Physics 2014-11-18 J. Gamboa , M. Loewe , F. Mendez , J. C. Rojas

We survey noncommutative spacetimes with coordinates being enveloping algebras of Lie algebras. We also explain how to do differential geometry on noncommutative spaces that are obtained from commutative ones via a Moyal-product type…

High Energy Physics - Theory · Physics 2007-05-23 S. Majid

Estimating causal effects is particularly challenging when outcomes arise in complex, non-Euclidean spaces, where conventional methods often fail to capture meaningful structural variation. We develop a framework for topological causal…

Methodology · Statistics 2026-03-04 Kwangho Kim , Hajin Lee

We consider spacelike surfaces in the four-dimensional Minkowski space and introduce geometrically an invariant linear map of Weingarten-type in the tangent plane at any point of the surface under consideration. This allows us to introduce…

Differential Geometry · Mathematics 2012-05-30 Georgi Ganchev , Velichka Milousheva

We construct an example which shows that two isocausal spacetimes, in the sense introduced by Garc\'ia-Parrado and Senovilla, may have c-boundaries which are not equal (more precisely, not equivalent, as no bijection between the completions…

Mathematical Physics · Physics 2015-05-27 J. L. Flores , J. Herrera , M. Sanchez

Identifying causal effects in the presence of unmeasured variables is a fundamental challenge in causal inference, for which proxy variable methods have emerged as a powerful solution. We contrast two major approaches in this framework: (1)…

Methodology · Statistics 2026-05-12 Helen Guo , Elizabeth L. Ogburn , Ilya Shpitser

A formulation of Einstein equations is presented that could yield advantages in the study of collisions of binary compact objects during regimes between linear-nonlinear transitions. The key idea behind this formulation is a separation of…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Pablo Laguna

This article is devoted to the noncommutative version of the Laplace transformation. New types of the direct and inverse transformations of the Laplace type over general Cayley-Dickson algebras, in particular, also the skew field of…

Complex Variables · Mathematics 2010-03-16 S. V. Ludkovsky