Homothetic vectors and higher-order Lagrangian theories of gravity

1989 ◽  
Vol 6 (9) ◽  
pp. 1213-1218 ◽  
Author(s):  
A A Coley
2021 ◽  
Vol 104 (2) ◽  
Author(s):  
Scott E. Perkins ◽  
Remya Nair ◽  
Hector O. Silva ◽  
Nicolás Yunes

2014 ◽  
Vol 11 (S308) ◽  
pp. 119-120
Author(s):  
Takayuki Tatekawa ◽  
Shuntaro Mizuno

AbstractZel'dovich proposed Lagrangian perturbation theory (LPT) for structure formation in the Universe. After this, higher-order perturbative equations have been derived. Recently fourth-order LPT (4LPT) have been derived by two group. We have shown fifth-order LPT (5LPT) In this conference, we notice fourth- and more higher-order perturbative equations. In fourth-order perturbation, because of the difference in handling of spatial derivative, there are two groups of equations. Then we consider the initial conditions for cosmological N-body simulations. Crocce, Pueblas, and Scoccimarro (2007) noticed that second-order perturbation theory (2LPT) is required for accuracy of several percents. We verify the effect of 3LPT initial condition for the simulations. Finally we discuss the way of further improving approach and future applications of LPTs.


2019 ◽  
Vol 353 ◽  
pp. 467-490 ◽  
Author(s):  
Evan J. Lieberman ◽  
Xiaodong Liu ◽  
Nathaniel R. Morgan ◽  
Darby J. Luscher ◽  
Donald E. Burton

1994 ◽  
Vol 09 (13) ◽  
pp. 2229-2244 ◽  
Author(s):  
ALVARO DE SOUZA DUTRA

We calculate the Green functions of the two versions of the generalized Schwinger model, the anomalous and the nonanomalous one, in their higher order Lagrangian density form. Furthermore, it is shown through a sequence of transformations that the bosonized Lagrangian density is equivalent to the former, at least for the bosonic correlation functions. The introduction of the sources from the beginning, leading to a gauge-invariant source term, is also considered. It is verified that the two models have the same correlation functions only if the gauge-invariant sector is taken into account. Finally, there is presented a generalization of the Wess-Zumino term, and its physical consequences are studied, in particular the appearance of gauge-dependent massive excitations.


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