24 research outputs found
On certain new integrable second order nonlinear differential equations and their connection with two dimensional Lotka-Volterra system
In this paper, we consider a second order nonlinear ordinary differential
equation of the form
,
where 's, are arbitrary parameters. By using the modified
Prelle-Singer procedure, we identify five new integrable cases in this equation
besides two known integrable cases, namely (i) and (ii) . Among these five, four equations admit time dependent first
integrals and the remaining one admits time independent first integral. From
the time independent first integral, nonstandard Hamiltonian structure is
deduced thereby proving the Liouville sense of integrability. In the case of
time dependent integrals, we either explicitly integrate the system or
transform to a time-independent case and deduce the underlying Hamiltonian
structure. We also demonstrate that the above second order ordinary
differential equation is intimately related to the two-dimensional
Lotka-Volterra (LV) system. From the integrable parameters of above nonlinear
equation and all the known integrable cases of the latter can be deduced
thereby.Comment: Accepted for publication in J. Math. Phy
Emergence of chaotic hysteresis in a second-order non-autonomous chaotic circuit
The observation of hysteresis in the dynamics of a third-order autonomous
chaotic system namely, the {\it{Chua's}} circuit has been reported recently
\cite{Gomes2023}. In the present work, we make a detailed study on the
emergence of dynamical hysteresis in a simple second-order non-autonomous
chaotic system namely, the {\it{Murali-Lakshmanan-Chua }} (MLC) circuit. The
experimental realization of chaotic hysteresis is further validated by
numerical simulation and analytical solutions. The presence of chaotic
hysteresis in a second-order non-autonomous electronic circuit is reported for
the first time. Multistable regions are observed in the dynamics of MLC with
constant bias.Comment: 27 Pages, 10 figure
A nonlocal connection between certain linear and nonlinear ordinary differential equations: extension to coupled equations
Identifying integrable coupled nonlinear ordinary differential equations (ODEs) of dissipative type and deducing their general solutions are some of the challenging tasks in nonlinear dynamics. In this paper we undertake these problems and unearth two classes of integrable coupled nonlinear ODEs of arbitrary order. To achieve these goals we introduce suitable nonlocal transformations in certain linear ODEs and generate the coupled nonlinear ODEs. In particular, we show that the problem of solving these classes of coupled nonlinear ODEs of any order effectively reduces to solving a single first order nonlinear ODE. We then describe a procedure to derive explicit general solutions for the identified integrable coupled ODEs, when the above mentioned first order nonlinear ODE reduces to a Bernoulli equation. The equations which we generate and solve include the two coupled versions of modified Emden equations (in second order), coupled versions of Chazy equations (in third order), and their variants, higher dimensional coupled Ricatti and Abel's chains, as well as a new integrable chain and higher order equations
Non-standard conserved Hamiltonian structures in dissipative/damped systems : Nonlinear generalizations of damped harmonic oscillator
In this paper we point out the existence of a remarkable nonlocal
transformation between the damped harmonic oscillator and a modified Emden type
nonlinear oscillator equation with linear forcing, which preserves the form of the time
independent integral, conservative Hamiltonian and the equation of motion.
Generalizing this transformation we prove the existence of non-standard
conservative Hamiltonian structure for a general class of damped nonlinear
oscillators including Li\'enard type systems. Further, using the above
Hamiltonian structure for a specific example namely the generalized modified
Emden equation , where ,
and are arbitrary parameters, the general solution is obtained
through appropriate canonical transformations. We also present the conservative
Hamiltonian structure of the damped Mathews-Lakshmanan oscillator equation. The
associated Lagrangian description for all the above systems is also briefly
discussed.Comment: Accepted for publication in J. Math. Phy
Dynamics of a Completely Integrable -Coupled Li\'enard Type Nonlinear Oscillator
We present a system of -coupled Li\'enard type nonlinear oscillators which
is completely integrable and possesses explicit time-independent and
time-dependent integrals. In a special case, it becomes maximally
superintegrable and admits time-independent integrals. The results are
illustrated for the N=2 and arbitrary number cases. General explicit periodic
(with frequency independent of amplitude) and quasiperiodic solutions as well
as decaying type/frontlike solutions are presented, depending on the signs and
magnitudes of the system parameters. Though the system is of a nonlinear damped
type, our investigations show that it possesses a Hamiltonian structure and
that under a contact transformation it is transformable to a system of
uncoupled harmonic oscillators.Comment: One new section adde
Nonlocal symmetries of a class of scalar and coupled nonlinear ordinary differential equations of any order
In this paper we devise a systematic procedure to obtain nonlocal symmetries
of a class of scalar nonlinear ordinary differential equations (ODEs) of
arbitrary order related to linear ODEs through nonlocal relations. The
procedure makes use of the Lie point symmetries of the linear ODEs and the
nonlocal connection to deduce the nonlocal symmetries of the corresponding
nonlinear ODEs. Using these nonlocal symmetries we obtain reduction
transformations and reduced equations to specific examples. We find the reduced
equations can be explicitly integrated to deduce the general solutions for
these cases. We also extend this procedure to coupled higher order nonlinear
ODEs with specific reference to second order nonlinear ODEs.Comment: Accepted for publication in J. Phys. A Math. Theor. 201