Synchronous Lagrangian variational principles in General Relativity

@article{50361,
   author = {Cremaschini, Claudio and Tessarotto, Massimo},
   article_location = {DE - Spolková republika Německo},
   article_number = {6},
   doi = {http://dx.doi.org/10.1140/epjp/i2015-15123-4},
   keywords = {synchronous variational principle; classical field theory; general relativity},
   language = {eng},
   issn = {2190-5444},
   journal = {The European Physical Journal Plus},
   title = {Synchronous Lagrangian variational principles in General Relativity},
   url = {https://link.springer.com/article/10.1140/epjp/i2015-15123-4},
   volume = {130},
   year = {2015}
}

TY  - JOUR
ID  - 50361
AU  - Cremaschini, Claudio - Tessarotto, Massimo
PY  - 2015
TI  - Synchronous Lagrangian variational principles in General Relativity
JF  - The European Physical Journal Plus
VL  - 130
IS  - 6
SP  - "123-1"-"123-21"
EP  - "123-1"-"123-21"
SN  - 21905444
KW  - synchronous variational principle
KW  - classical field theory
KW  - general relativity
UR  - https://link.springer.com/article/10.1140/epjp/i2015-15123-4
N2  - The problem of formulating synchronous variational principles in the context of General Relativity is discussed. Based on the analogy with classical relativistic particle dynamics, the existence of variational principles is pointed out in relativistic classical field theory which are either asynchronous or synchronous. The historical Einstein-Hilbert and Palatini variational formulations are found to belong to the first category. Nevertheless, it is shown that an alternative route exists which permits one to cast these principles in terms of equivalent synchronous Lagrangian variational formulations. The advantage is twofold. First, synchronous approaches allow one to overcome the lack of gauge symmetry of the asynchronous principles. Second, the property of manifest covariance of the theory is also restored at all levels, including the symbolic Euler-Lagrange equations, with the variational Lagrangian density being now identified with a 4-scalar. As an application, a joint synchronous
ER  - 

CREMASCHINI, Claudio a Massimo TESSAROTTO. Synchronous Lagrangian variational principles in General Relativity. \textit{The European Physical Journal Plus}. DE - Spolková republika Německo, 2015, roč.~130, č.~6, s.~''123-1''-''123-21'', 21 s. ISSN~2190-5444. Dostupné z: https://dx.doi.org/10.1140/epjp/i2015-15123-4.