Changing variables in the Schrodinger equation

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The discussion focuses on transforming the Schrödinger equation for two interacting particles into center of mass coordinates, R and r. The main question is whether the wave function in original coordinates, ψ(x,y,t), can be expressed in terms of the new coordinates as φ(R,r,t). The user seeks to establish a one-to-one mapping between the original coordinates (x,y) and the center of mass coordinates (R,r). If such a mapping exists, it would confirm the equivalence of the wave functions in both coordinate systems. The conversation emphasizes the importance of understanding this transformation for clarity in quantum mechanics.
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Suppose I have a Schrodinger equation for two interacting particles located at x and y; so, something like
<br /> \left( i \frac{\partial}{\partial t} + \frac{1}{2m_x} \frac{\partial^2}{\partial x^2} + \frac{1}{2m_y} \frac{\partial^2}{\partial y^2} + V(x-y) \right) \psi(x,y,t) = 0.<br />
Now, I want to shift to center of mass coordinates R and r and write the Hamiltonian in terms of them. The resulting Schrodinger equation looks something like
<br /> \left( i \frac{\partial}{\partial t} + H(R,r) \right) \varphi(R,r,t) = 0.<br />
Question: is it true that
<br /> \psi(x,y,t) = \varphi \left(\frac{m_x x + m_y y}{m_x + m_y},x-y,t\right)?<br />
If so, why? I have been trying to prove this but have so far just been going around in circles it seems...
 
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Can you write ##x## and ##y## in terms of ##R## and ##r##, such that you have a one-to-one mapping between the two? If yes, then there is no difference between expressing a function in terms of ##(x,y)## or of ##(R,r)##.
 
Time reversal invariant Hamiltonians must satisfy ##[H,\Theta]=0## where ##\Theta## is time reversal operator. However, in some texts (for example see Many-body Quantum Theory in Condensed Matter Physics an introduction, HENRIK BRUUS and KARSTEN FLENSBERG, Corrected version: 14 January 2016, section 7.1.4) the time reversal invariant condition is introduced as ##H=H^*##. How these two conditions are identical?

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