Calogero-Moser systems are integrable systems with singular pair interactions. The rational Calogero-Moser system is the Hamiltonian system defined by
|
(1)
|
where ,
the coordinates
are distinct real numbers, the momenta
are real, and
. Hamilton's equations
give
|
(2)
| |||
|
(3)
|
Its Lax pair can be written using matrices and
with entries
|
(4)
| |||
|
(5)
| |||
|
(6)
| |||
|
(7)
|
where the off-diagonal formulas apply for and
is the imaginary unit.
The evolution equation is
|
(8)
|
so the eigenvalues of are conserved. The matrix traces
|
(9)
|
for ,
...,
are integrals of motion that commute under the
Poisson bracket and are functionally independent
on a dense open set. In particular,
(Moser 1975; Etingof 2007, pp. 11-19).
Adding the harmonic term , where
, gives equilibrium coordinates
|
(10)
|
where the
are the zeros of the Hermite
polynomial
with leading coefficient
(Odake and Sasaki 2002). The quantum rational model with
harmonic confinement is a Calogero-Sutherland
model.
The equilibrium coordinates for and
, 5, and 8 are illustrated above. The blue curves are the
Hermite polynomials multiplied by
and scaled independently for display. This positive
factor preserves their zeros, which are marked as the orange
equilibrium positions.