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Joseph Kouneiher

Publications and source records attributed to Joseph Kouneiher.

12 recordsLinked to original sources
arXiv2024

Pierre Cartier: A Visionary Mathematician

This article reflects on the life and mathematical contributions of Pierre Cartier, a distinguished figure in 20th- and 21st-century mathematics. As a key member of the Bourbaki collective, Cartier played a pivotal role in the formalization and modernization of mathematics. His work spanned fields such as algebraic geometry, representation theory, mathematical physics, and category theory, leaving an indelible mark on the discipline. Beyond his technical achievements, Cartier was celebrated for his intellectual generosity and humanistic approach to science, shaping not only mathematical thought but also the broader cultural understanding of the field.

math.HO↗
arXiv2023

The relation between the canonical Hamilton-Jacobi equation and the covariant Hamilton-Jacobi equation for Maxwell's electrodynamics

The aim of this paper is to understand the relation between the canonical Hamilton-Jacobi equation for Maxwell's electrodynamics, which is an equation with variational derivatives for a functional of field configurations, and the covariant (De Donder-Weyl) Hamilton-Jacobi equation, which is a partial derivative equation on a finite dimensional space of vector potentials and spacetime coordinates. We show that the procedure of spacetime splitting applied to the latter allows us to reproduce both the canonical Hamilton-Jacobi equation and the Gauss law constraint in the Hamilton-Jacobi form without a recourse to the canonical Hamiltonian analysis. Our consideration may help to analyze the quasi-classical limit of the connection between the standard quantization in field theory based on the canonical Hamiltonian formalism with a preferred time dimension and the precanonical quantization that uses the De Donder-Weyl Hamiltonian formulation where space and time dimensions treated equally.

math-ph↗
arXiv2019

Sir Michael Atiyah, a Knight Mathematician A tribute to Michael Atiyah, an inspiration and a friend

Sir Michael Atiyah was considered as one of the world's foremost mathematicians, He is best known for his work in algebraic topology and the co-development of a branch of mathematics called topological K-theory together with the Atiyah-Singer index theorem for which he received Fields Medal (1966). He received also the Abel Prize (2004) along with Isadore M. Singer for their discovery and proof of the index theorem, bringing together topology, geometry and analysis, and their outstanding role in building new bridges between mathematics and theoretical physics. Indeed, his work has helped theoretical physicists to advance their understanding of quantum field theory and general relativity.

math.HO↗
arXiv2015

Superlogic Manifolds and Geometric approach to Quantum Logic

The main purpose of this paper is to present a new approach to logic or what we will call superlogic. This approach constitutes a new way of looking at the connection between quantum mechanics and logic. It is a {\it geometrisation} of the quantum logic. Note that this superlogic is not distributive reflecting a good propriety to describe quantum mechanics, non commutative spaces and contains a nilpotent element.

quant-ph↗
arXiv2004

Covariant Hamiltonian formalism for the calculus of variations with several variables: Lepage--Dedecker versus de Donder--Weyl

The main purpose in the present paper is to build a Hamiltonian theory for fields which is consistent with the principles of relativity. For this we consider detailed geometric pictures of Lepage theories in the spirit of Dedecker and try to stress out the interplay between the Lepage-Dedecker (LP) description and the (more usual) de Donder-Weyl (dDW) one. One of the main points is the fact that the Legendre transform in the dDW approach is replaced by a Legendre correspondence in the LP theory (This correspondence behaves differently: ignoring the singularities whenever the Lagrangian is degenerate).

math-ph↗
arXiv2004

The notion of observable in the covariant Hamiltonian formalism for the calculus of variations with several variables

This papers is concerned with multisymplectic formalisms which are the frameworks for Hamiltonian theories for fields theory. Our main purpose is to study the observable $(n-1)$-forms which allows one to construct observable functionals on the set of solutions of the Hamilton equations by integration. We develop here two different points of view: generalizing the law $\{p,q\} = 1$ or the law $dF/dt = \{H,F\}$. This leads to two possible definitions; we explore the relationships and the differences between these two concepts. We show that -- in contrast with the de Donder--Weyl theory -- the two definitions coincides in the Lepage--Dedecker theory.

math-ph↗
arXiv2002

Covariant Hamiltonian formalism for the calculus of variations with several variables

The main purpose in the present paper is to build a Hamiltonian theory for fields which is consistent with the principles of relativity. For this we consider detailed geometric pictures of Lepage theories in the spirit of Dedecker and try to stress out the interplay between the Lepage-Dedecker (LP) description and the (more usual) de Donder-Weyl (dDW) one. For instance the Legendre transform in the dDW approach is replaced by a Legendre correspondence in the LP theory, while ignoring singularities whenever the Lagrangian is degenerate. Moreover we show that there exist two different definitions of the observable (n-1)-forms which allows one to construct observable functionals by integration (which correspond to two different points of view: generalizing the law {p,q} = 1 or the law dF\dt = {H,F}), oddly enough we prove that these two definitions coincides only in the LP situation. Finally other contributions concerning this subject and examples are also given.

math-ph↗
arXiv2000

Finite dimesional Hamiltonian formalism for gauge and field theories

We discuss in this paper the canonical structure of classical field theory in finite dimensions within the {\it{pataplectic}} Hamiltonian formulation, where we put forward the role of Legendre correspondance. We define the generalized Poisson $\mathfrak{p}$-brackets which are the analogues of the Poisson bracket on forms. We formulate the equations of motion of forms in terms of $\mathfrak{p}$-brackets. As illustration of our formalism we present three examples: the interacting scalar fields, conformal string theory and the electromagnetic field.

math-ph↗
arXiv2000

Hamiltonian formalism with several variables and quantum field theory, PartI

We discuss in this paper the canonical structure of classical field theory in finite dimensions within the {\it{pataplectic}} hamiltonian formulation, where we put forward the role of Legendre correspondance. We define the Poisson $\mathfrak{p}$-brackets and $\mathfrakω$-brackets which are the analogues of the Poisson bracket on forms. We formulate the equations of motion of forms in terms of $\mathfrak{p}$-brackets and $\mathfrakω$-brackets with the $n$-form ${\cal H}ω$. As illustration of our formalism we present two examples: the interacting scalar fields and conformal string theory.

math-ph↗
arXiv1999

Superstrings, Unifications and dualities

I describe our understanding of physics near the planck length, in particular the great progress of the last four years in string theory. Superstring theory, and a recent extension called M theory, are leading candidates for a quantum theory that unifies gravity with the other forces. As such, they are certainly not ordinary quantum field theories. However, recent duality conjectures suggest that a more complete definition of these theories can be provided by the large N limits of suitably chosen U(N) gauge theories associated to the asymptotic boundary of spacetime.

hep-th↗