Remarks on the method of comparison equations (generalized WKB method) and the generalized Ermakov-Pinney equation
@inproceedings{Kamenshchik2005RemarksOT, title={Remarks on the method of comparison equations (generalized WKB method) and the generalized Ermakov-Pinney equation}, author={Alexander Yu. Kamenshchik and Mattia Luzzi and Giovanni Venturi}, year={2005} }
The connection between the method of comparison equations (generalized WKB method) and the Ermakov-Pinney equation is established. A perturbative scheme of solution of the generalized Ermakov-Pinney equation is developed and is applied to the construction of perturbative series for second-order differential equations with and without turning points.
14 Citations
The method of comparison equations for cosmological perturbations
- Physics
- 2006
We apply the method of comparison equations to study cosmological perturbations during inflation, obtaining the full power spectra of scalar and tensor perturbations to first and to second order in…
Cosmological aspects of the Eisenhart–Duval lift
- Physics
- 2018
A cosmological extension of the Eisenhart–Duval metric is constructed by incorporating a cosmic scale factor and the energy-momentum tensor into the scheme. The dynamics of the spacetime is governed…
Method of comparison equations for Schwarzschild black holes
- Physics
- 2006
We employ the method of comparison equations to study the propagation of a massless minimally coupled scalar field on the Schwarzschild background. In particular, we show that this method allows us…
Scalar field exact solutions for non-flat FLRW cosmology: a technique from non-linear Schrödinger-type formulation
- Physics
- 2009
We report a method of solving for canonical scalar field exact solution in a non-flat FLRW universe with barotropic fluid using non-linear Schrödinger (NLS)-type formulation in comparison to the…
Nonlinear Schrödinger-type formulation of scalar field cosmology: Two barotropic fluids and exact solutions
- Physics, Mathematics
- 2020
Time-independent nonlinear Schrodinger-type (NLS) formulation of FRW cosmology with canonical scalar field is considered in the case of two barotropic fluids. We derived Friedmann formulation varia...
Solvable Time-Dependent Models in Quantum Mechanics
- Physics
- 2011
In the traditional setting of quantum mechanics, the Hamiltonian operator does not depend on time. While some Schrödinger equations with time-dependent Hamiltonians have been solved, explicitly…
Quantum gravity, time, bounces, and matter
- PhysicsPhysical Review D
- 2018
In the context of Quantum Cosmology and the Wheeler-DeWitt equation we investigate the possible effects of a non semiclassical wave-function of the universe on the evolution of the inflationary…
Energy exchange in the dissipative time-dependent harmonic oscillator: Physical interpretation of the Ermakov invariant
- Materials SciencePramana
- 2022
The energy of a mechanical system as well as other invariants can be obtained using a complementary variable formulation. This approach is extended here to systems with a dissipative force. The…
Dark energy in some integrable and nonintegrable FRW cosmological models
- Physics
- 2011
One of the greatest challenges in cosmology today is to determine the nature of dark energy, the sourse of the observed present acceleration of the Universe. Besides the vacuum energy, various dark…
Cosmological and astrophysical observables from field theory in curved backgrounds
- Physics
- 2019
The framework of effective field theory has provided valuable insights needed to understand the evolution of physical systems at different energy scales. In particular, when comparing the…
References
SHOWING 1-10 OF 16 REFERENCES
Asymptotics and Special Functions
- Education
- 1974
A classic reference, intended for graduate students mathematicians, physicists, and engineers, this book can be used both as the basis for instructional courses and as a reference tool.
Quantum mechanics
- PhysicsNature
- 1975
Quantum Mechanics for Organic Chemists.By Howard E. Zimmerman. Pp. x + 215. (Academic: New York and London, May 1975.) $16.50; £7.90.
Phys. Rev
- Phys. Rev
- 1953
J. Math. Phys
- J. Math. Phys
- 1968
Univ . Izv . Kiev , series III 9 ( 1880 ) 1 . [ 9 ] E . Pinney
- Proc . Amer . Math . Soc .
- 2005