University of Delhi, Delhi, India Route to chaos Awadhesh Prasad University of Delhi, Delhi, India
-- Models -- Functions -- Objects
Length of lightening? Detection of direction of information flow in coupled complex systems
Length of a tree? Detection of direction of information flow in coupled complex systems
Length of coastline
Area of surface?
Examples Linear: Point, Line, Plane, Cube Nonlinear: Sphere, length of a tree Detection of direction of information flow in coupled complex systems
Linear vs Nonlinear Detection of direction of information flow in coupled complex systems
Differential equation: Linear Nonlinear
Differential equation: Linear Nonlinear
Pendulum Individual/single
Pendulum: Linear vs Nonlinear T0=time at vertical which th=0 sn Jacobian Elliptic function
Pendulum: Linear vs Nonlinear T0=time at vertical which th=0
Center Linear Pendulum Damped Undamped Stable T0=time at vertical which th=0 Center Stable
Nonlinear pendulum Undapmed Damped Center/saddle Stable & Unstable T0=time at vertical which th=0 Center/saddle Stable & Unstable
Solutions = ? + Dissipation Nonlinearity
Fixed/stationary points 1D Systems Fixed/stationary points
Fixed/stationary points 1D Systems Fixed/stationary points U S U S U S U S
2D Systems
>2D Systems
Solutions Invariants Attractors
Solutions -- Fixed point -- Periodic -- Quasiperiodic -- Chaotic
Solutions -- Fixed point Nonlinear Linear -- Periodic -- Quasiperiodic -- Chaotic
Fixed point Solutions l=a ib
Periodic Solutions Unstable fixed points
Periodic solutions
Quasiperiodic
Quasiperiodic
Stable/unstable periodic orbits Chaos!!
Chaotic Solutions
Chaotic Solutions
Properties of chaos -- geometrically strange -- temporally irregular -- sensitive to initial conditions Due to UPO?
Unstable Periodic Orbits (UPOs)
Bifurcation Qualitative change in dynamics as parameter varies Sand piling Heartbeat
Chaos to Periodic: Heart Attack Christini D J et al. PNAS 98, 5827(2001)
Montage
Onset of a temporal lobe epileptic seizure Ref. L. Iasemidis
EEG: Epileptic Patient (temporal lobe epilepsy) Preictal ictal postictal minutes
Aim Periodic Chaotic Routes? Chaotic Chaos
Period doubling: Laser
End