Nosso objetivo € consideraruma ampla classe de equaçöes diferenciais ordinarias da qual (*) faz parte, e que aparecem via a equação de Euler– Lagrange no. Palavras-chave: Cálculo Variacional; Lagrangeano; Hamiltoniano; Ação; Equações de Euler-Lagrange e Hamilton-Jacobi; análise complexa (min, +); Equações. Propriedades de transformação da função de Lagrange de covariância das equações do movimento no nível adequado para o ensino de wide class of transformations which maintain the Euler-Lagrange structure of the.

Author: Taukinos Nadal
Country: Trinidad & Tobago
Language: English (Spanish)
Genre: Medical
Published (Last): 9 April 2007
Pages: 423
PDF File Size: 5.99 Mb
ePub File Size: 20.45 Mb
ISBN: 430-9-30721-456-5
Downloads: 7094
Price: Free* [*Free Regsitration Required]
Uploader: Nar

To conclude this section we briefly discuss the invariance properties of the Hamiltonian. Certainly, the creation has been flawed in so far as evil exists in the world, but this does not prevent anybody from considering that there is an almighty Creator, omniscient and infinitely good.

How can our analysis naturally lead to some simple result concerning a theory of transformations in quantum mechanics? The complex action S zt verifies the complex Jamilton-Jacobi equations. You’d never have a budget that looks like a circle and this kind of random configuration for your revenue but in principle, you know what I mean, right?

So to remind you of the setup, this is gonna be a constrained optimization problem setup so we’ll have some kind of multivariable function.

Equilibrium and Euler-Lagrange equation for hyperelastic materials

On the other hand, when one performs such a change of variables, it may occur that the new generalized coordinate Q, depending also on the old momentum p, is unsuitable for the local description of the configuration space. Nature, We have so proved that the scalar invariance of the Hamiltonian is necessary and sufficient condition for a canonoid map to be canonical.

So this second component of our Lagrangian equals zero equation is just the second function that we’ve seen in a lot of these examples that we’ve been doing where you set one of the gradient vectors proportional to the other one, and the only real difference here from stuff that we’ve seen already, and even then it’s not that different is that what happens when we take the partial derivative of this Lagrangian with respect to lambda, and I’ll go ahead and give it that kind of green lambda color here.


It is a pragmatic way to consider the existence of this wave function, as stated by P.

Moreover, it is well known that the point transformations in phase space belong to a proper subset of the canonical transformations. In this case, I put in four so you write minus four.

The Lagrangian

In fact, it all looks just identical. The principles of Quantum Theory. John Wiley and Sons, 3rd edition, Further, as a direct consequence of the Hamilton principle see Ref.

Bousquet, Lausanne et Geneva Herein, we considered the most general class of covariance both for Hamiltonian and Lagrangian mechanics and proved that neither the Hamiltonian nor the Lagrangian functions are, in general, scalar fields.

In the previous section, when dealing with classical mechanics, we asked the invariance of the condition. Press, Cambridge,4 re ed.

Euler–Lagrange equation – Wikipedia

One can generalize the resolution of Hamilton-Jacobi equations for the complex ones. A necessary condition for a differentiable functional to eauao an extremum on some function is that its functional derivative at that function vanishes, which is granted by the last equation.

The third equation that we need to solve. We apply this complex variational calculus to Born-Infeld theory of electromagnetism and show why it does not exhibit nonlinear effects. Finally we analyze a simple example of quantum canonical transformation.

A time-independent canonoid but non canonical transformation never leaves invariant its Hamiltonian. The Hamiltonian framework Hence, let us assume that a map of the kind 4enjoying condition 7 for a dynamics described by q, ttransforms the equai of motion, leading to a dynamics described by Q, t.

In fact, by differentiating 19 eqquao respect to q and successively with respect to pand taking into account that we obtain In this way we have proved the following Proposition 1: Complex calculus of variations.

Theory of the transformations and scalar invariance of the Lagrangian. In the early s, Maupertuis was involved in a violent controversy: This is clearly a stronger condition and, actually, only a few transformations can be equqo to the quantum framework.


We will speak of scalar invariance to express this outcome.

In order to get the solution of those equations, it has been necessary to use complex variables. So kind of the whole point of this Lagrangian is that it turns our constrained optimization problem involving R and B and this new made-up variable lambda into an unconstrained optimization problem where we’re just setting the gradient of some function equal to zero so computers can often do that really quickly so if you just hand the computer this function, it will be able to find you an answer whereas it’s harder to say, “Hey computer, “I want you to think about when the gradients are parallel, “and also consider this constraint function.

Images: The World’s Most Beautiful Equations | lookle | Pinterest | Physics, Equation and Math

Euler-lagrangf you’ll see it in bold if it’s in a textbook but what we’re really saying is we set those three different functions, the three different partial derivatives all equal to zero so this is just a euler-layrange like closed form, compact way of saying that all of its partial derivatives is equal to zero, and let’s go ahead and think about what those partial derivatives actually are.

You’re kind of modeling your revenues based on different choices you could make running that company, and the constraint that you’d have would be, let’s say a budget so I’m just gonna go ahead and write budget or B for budget here so you’re trying to maximize revenues, and then you have some sort of dollar limit for what you’re willing to spend, and these, of course, are just kind of made-up functions.

In classical mechanicsit is equivalent to Newton’s laws of motionbut it has the advantage that it takes the same form in any system of generalized coordinatesand it is better suited to generalizations.