scholarly journals Geometry of multisymplectic Hamiltonian first-order field theories

2000 ◽  
Vol 41 (11) ◽  
pp. 7402-7444 ◽  
Author(s):  
Arturo Echeverria-Enrı́quez ◽  
Miguel C. Muñoz-Lecanda ◽  
Narciso Román-Roy
Keyword(s):  
2018 ◽  
Vol 109 (6) ◽  
pp. 1343-1376
Author(s):  
Santiago Capriotti ◽  
Eduardo García-Toraño Andrés

2002 ◽  
Vol 29 (12) ◽  
pp. 687-699 ◽  
Author(s):  
A. Echeverría-Enríquez ◽  
M. C. Muñoz-Lecanda ◽  
N. Román-Roy

We give a geometric formulation of the field equations in the Lagrangian and Hamiltonian formalisms of classical field theories (of first order) in terms of multivector fields. This formulation enables us to discuss the existence and nonuniqueness of solutions of these equations, as well as their integrability.


The Euler-Lagrange equations corresponding to a Lagrange density which is a function of the metric tensor g ij and its first two derivatives together with the first derivative of a vector field ψ i are investigated. In general, the Euler-Lagrange equations obtained by variation of g ij are of fourth order in g ij and third order in ψ i . It is shown that in a four dimensional space the only Euler-Lagrange equations which are of second order in g ij and first order in ψ i are the Einstein field equations (with an energy-momentum term). Various conditions are obtained under which the Einstein-Maxwell field equations are then an inevitable consequence.


2021 ◽  
Vol 81 (6) ◽  
Author(s):  
Vincenzo Branchina ◽  
Alberto Chiavetta ◽  
Filippo Contino

AbstractA formal expansion for the Green’s functions of a quantum field theory in a parameter $$\delta $$ δ that encodes the “distance” between the interacting and the corresponding free theory was introduced in the late 1980s (and recently reconsidered in connection with non-hermitian theories), and the first order in $$\delta $$ δ was calculated. In this paper we study the $${\mathcal {O}}(\delta ^2)$$ O ( δ 2 ) systematically, and also push the analysis to higher orders. We find that at each finite order in $$\delta $$ δ the theory is non-interacting: sensible physical results are obtained only resorting to resummations. We then perform the resummation of UV leading and subleading diagrams, getting the $${\mathcal {O}}(g)$$ O ( g ) and $${\mathcal {O}}(g^2)$$ O ( g 2 ) weak-coupling results. In this manner we establish a bridge between the two expansions, provide a powerful and unique test of the logarithmic expansion, and pave the way for further studies.


1983 ◽  
Vol 38 (12) ◽  
pp. 1293-1295
Author(s):  
D. Großer

Abstract A field theory which is based entirely on fermion fields is non-renormalizable if the kinetic energy contains only derivatives of first order and therefore higher derivatives have to be included. Such field theories may be useful for describing preons and their interaction. In this note we show that a spinor field which satisfies a higher order field equation with an arbitrary nonlinear selfinteraction can be written as a sum of fields which satisfy first order equations.


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Dibakar Roychowdhury

In this paper, based on the basic principles of thermodynamics, we explore the hydrodynamic regime of interacting Lifshitz field theories in the presence of broken rotational invariance. We compute the entropy current and discover new dissipative effects which are consistent with the principle of local entropy production in the fluid. In our analysis, we consider both the parity even and the parity odd sector upto first order in the derivative expansion. Finally, we argue that the present construction of the paper could be systematically identified as that of the hydrodynamic description associated with spin waves (away from the domain of quantum criticality) under certain limiting conditions.


2020 ◽  
Vol 102 (6) ◽  
Author(s):  
Verónica Errasti Díez ◽  
Markus Maier ◽  
Julio A. Méndez-Zavaleta ◽  
Mojtaba Taslimi Tehrani

1991 ◽  
Vol 1 (4) ◽  
pp. 345-374 ◽  
Author(s):  
J.F. Cariñena ◽  
M. Crampin ◽  
L.A. Ibort
Keyword(s):  

2015 ◽  
Vol 12 (09) ◽  
pp. 1560022 ◽  
Author(s):  
Celso de Araujo Duarte

Following the line of the history, if by one side the electromagnetic theory was consolidated on the 19th century, the emergence of the special and the general relativity theories on the 20th century opened possibilities of further developments, with the search for the unification of the gravitation and the electromagnetism on a single unified theory. Some attempts to the geometrization of the electromagnetism emerged in this context, where these first models resided strictly on a classical basis. Posteriorly, they were followed by more complete and embracing quantum field theories. The present work reconsiders the classical viewpoint, with the purpose of showing that at first-order of approximation the electromagnetism constitutes a geometric structure aside other phenomena as gravitation, and that magnetic monopoles do not exist at least up to this order of approximation. Even though being limited, the model is consistent and offers the possibility of an experimental test of validity.


2002 ◽  
Vol 2002 (09) ◽  
pp. 036-036 ◽  
Author(s):  
Ludde Edgren ◽  
Niclas Sandström

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