Strange Hamilton Jacobi equation

In summary, the equation given can be considered as the Hamilton-Jacobi equation for a particle under a potential Vtotal=V(x)+(LS) where S is the action, with the potential being non-conservative and representing virtual work.
  • #1
eljose
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let be (dS/dt)+(gra(S))^2/2m+(LS)+V(x) where L is the Laplacian Operator and V is the potential...could it be considered as the Hamiltan Jacobi equation for a particle under a potential Vtotal=V(x)+(LS) where S is the action
 
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  • #2
eljose said:
let be (dS/dt)+(gra(S))^2/2m+(LS)+V(x) where L is the Laplacian Operator and V is the potential...could it be considered as the Hamiltan Jacobi equation for a particle under a potential Vtotal=V(x)+(LS) where S is the action

I assume you mean to equate to 0, i.e.:

[tex] \frac{\partial S}{\partial t}\right)+\frac{(\vec\nabla S)^2}{2m}+\vec\nabla S+V(q)=0 [/tex]

If we compare it to the Hamillton-Jacobi equation for the generating function S (a concept more general than the "action")

[tex] H\left(q,\frac{\partial S}{\partial q},t\right)+\frac{\partial S}{\partial t}=0 [/tex]

we find they are compatible provided we let

[tex] H\left(q,\frac{\partial S}{\partial q},t\right)=\frac{(\vec\nabla S)^2}{2m}+\vec\nabla S+V(q) [/tex]

Since [tex] p_i=\frac{\partial S}{\partial q_i} [/tex], we can rewrite it as

[tex] H\left(q_i,p_i,t\right)=\frac{(\sum_i p_i)^2}{2m}+\vec\nabla S+V(q) [/tex]

or

[tex] H=T+W [/tex]

where

[tex] W=\sum_i p_i+V(q_i) [/tex].

Here we see that [tex] W=f(p_i,q_i) [/tex], in other words the "potential" W is not conservative and the meaning of W is that of "virtual work". Is that the source of your doubts?
 
  • #3


The Strange Hamilton Jacobi equation is an interesting and complex equation that describes the dynamics of a particle under a potential. It is given by (dS/dt)+(gra(S))^2/2m+(LS)+V(x), where S is the action, L is the Laplacian Operator, and V is the potential. It can also be written as (dS/dt)+(H)+(V(x)), where H is the Hamiltonian operator.

This equation can be considered as the Hamilton Jacobi equation for a particle under a potential Vtotal=V(x)+(LS). The addition of the term (LS) in the potential reflects the presence of a non-conservative force, which can be thought of as a sort of friction or resistance acting on the particle. This term also makes the equation more complex and "strange" compared to the standard Hamilton Jacobi equation.

The presence of the Laplacian operator in the equation also adds a spatial component, making it more relevant for describing the motion of a particle in a physical space. This equation is often used in quantum mechanics to describe the behavior of particles in a potential field, and has many applications in various areas of physics and mathematics.

Overall, the Strange Hamilton Jacobi equation is a powerful tool for understanding the dynamics of particles under a potential and can provide valuable insights into the behavior of complex systems. Its complexity and versatility make it an important equation in the study of physics and its applications.
 

Related to Strange Hamilton Jacobi equation

1. What is the Strange Hamilton Jacobi equation?

The Strange Hamilton Jacobi equation is a partial differential equation in mathematical physics, named after the mathematicians William Rowan Hamilton and Carl Gustav Jacobi. It is used to describe the dynamics of a system of particles, and is commonly used in areas such as classical mechanics, quantum mechanics, and control theory.

2. What makes the Hamilton Jacobi equation "strange"?

The Hamilton Jacobi equation is considered "strange" because it is a second-order partial differential equation that cannot be solved by traditional methods. Instead, it requires the use of advanced mathematical techniques such as the method of characteristics or the Hamilton-Jacobi-Bellman equation.

3. What are the applications of the Hamilton Jacobi equation?

The Hamilton Jacobi equation has a wide range of applications in physics, engineering, and mathematics. It is used to study the dynamics of systems in classical and quantum mechanics, as well as control systems in engineering. It is also used in optimization problems, differential games, and geometric mechanics.

4. How does the Hamilton Jacobi equation relate to the principle of least action?

The Hamilton Jacobi equation is closely related to the principle of least action, which states that a physical system will follow the path that minimizes the action, a measure of the system's energy over time. The Hamilton Jacobi equation can be derived from the principle of least action, making it a powerful tool for understanding the dynamics of physical systems.

5. What are the main challenges in solving the Hamilton Jacobi equation?

The main challenges in solving the Hamilton Jacobi equation are the high dimensionality of the problem and the lack of analytical solutions. This means that numerical methods must be used, which can be computationally expensive and time-consuming. Additionally, the equation is often nonlinear and may have multiple solutions, making it difficult to find the global minimum or maximum solution.

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