The Lagrangian and the second derivative?

Context: Undergrad
Thread starter filip97
Start date Feb 3, 2019
Tags

Derivative Lagrangian Second derivative

Join the discussion

Registration is free. Ask a follow-up in this thread, or start your own.

1 reply · 2K views

filip97

Thread starter
Feb 3, 2019

Why Lagrangian not depend of higher derivatives of generalised coordinates ?

Discussion

Physics news on Phys.org

An elegant modification doubles the range of low-noise 'white lasers' in a single fiber
Researchers demonstrate first fully solution-processed solid-state polariton laser
Never-before-seen woven structure that forms naturally inside a crystal discovered

weirdoguy

Feb 3, 2019

Sometimes it depends, eg in general relativity or in elastomechanics. In most cases it does not, but there is no deeper explanation for that.

EDIT: AFAIK in QFT it would lead to inconsistencies, but I don't remember details.

Last edited: Feb 3, 2019

The Lagrangian and the second derivative?

Discussion

Graduate Quaternionic Rays instead of Complex

Graduate What are the most fundamental entities in the SM and QFT?

Undergrad If gravity is emergent, how does this affect string theory and loop quantum gravity?

Graduate Did Stephen Hawking fix his numerical mistake?

Undergrad Geodesics in quantum gravity: Missing Link

Graduate Using the Homotopy Analysis method in QG and BSM for solving nasty DEs

Graduate Is there some sort of transformation between Mandelstam parameters and Stokes parameters?

Undergrad Anomalous Ionization in the Central Molecular Zone by Sub-GeV Dark Matter

Graduate Decomposition of SU(2)-invariant spin network state in 3 dimensions

Undergrad 2D Ising Model Average Number of Domain Walls

Insights Revisiting the Velocity-Time Function

Insights Remote Operated Gate Control System

Insights AI Enriched Problem Solving

Insights Thinking Outside The Box Versus Knowing What’s In The Box

Insights Why Entangled Photon-Polarization Qubits Violate Bell’s Inequality

Insights Quantum Entanglement is a Kinematic Fact, not a Dynamical Effect

The Lagrangian and the second derivative?

Discussion

Similar threads

Undergrad Mathematical proof for the Lagrangian function

Undergrad Restoring S.I. units to a Lagrangian in natural units

Undergrad Lagrangian doesn't change when adding total time derivative

Undergrad Alternatives to the Lagrangian?

Undergrad Taylor expansion about lagrangian in noether

Undergrad Proving that the Lagrangian of a free particle is independent of q

Undergrad Why isn't the Lagrangian invariant under ##\theta## rotations?

Undergrad Lagrangian density of a linearly elastic string under gravity

High School Extending the Lagrangian of a double pendulum to more complex systems

Undergrad Lagrangian total time derivative for the velocity