arXiv subjects

Thanadon Kongkoom

Publications and source records attributed to Thanadon Kongkoom.

3 recordsLinked to original sources

arXiv2026

The $q$-deformed Calogero's Goldfish Systems

Searching for integrable models is a central theme in theoretical and mathematical physics, as such systems offer valuable insights into the underlying structure and symmetries of complex physical phenomena. In this work, we contribute to this pursuit by proposing a new class of one-dimensional many-body integrable systems, which we refer to as the $q$-deformed Calogero's Goldfish system. Our construction employs $q$-deformation of logarithmic and exponential functions inspired by Tsallis' formalism in non-extensive statistical mechanics. Notably, the model satisfies the double-zero condition on its solutions, underscoring its integrable nature and offering a novel perspective on deformation techniques within exactly solvable systems.

nlin.SI↗

arXiv2024

Lagrangian 1-form structure of Calogero-Moser type systems

We consider the variational principle for the Lagrangian 1-form structure for long-range models of Calogero-Moser (CM) type. The multiform variational principle involves variations with respect to both the field variables as well as the independent variables corresponding to deformations of the time-curves in a multi-time space. The ensuing generalised Euler-Lagrange (gEL) equations comprise a system of multi-time EL equations, as well as constraints from so-called `alien derivatives' and `corner equations' arising from how variations on different coordinate curves match up. The closure relation, i.e. closedness of the Lagrange 1-form on solutions of the EL system, guarantees the stationarity of the action functional under deformation of the time-curves, and hence the multidimensional consistency of the corresponding gEL system. Using this as an integrability criterion on the Lagrangian level, we apply the system to some ansätze on the kinetic form of the Lagrangian components, associated with models of CM type without specifying the potentials. We show that from this integrability criterion the general elliptic form of the three systems, Calogero-Moser, Ruijsenaars-Schneider, and Goldfish systems, can be derived. We extend the analysis to an associated Hamiltonian formalism, via Noether's theorem and by applying Legendre transformations. Thus, the multiform variational principle leads to a system of generalised Hamilton equations describing Hamiltonian commuting flows for the mentioned elliptic models.

nlin.SI↗

arXiv2023

Quantum integrability: Lagrangian 1-form case

A new notion of integrability called the multi-dimensional consistency for the integrable systems with the Lagrangian 1-form structure is captured in the geometrical language for quantum level. A zero-curvature condition, which implies the multi-dimensional consistency, will be a key relation, e.g. Hamiltonian operators. Therefore, the existence of the zero-curvature condition directly leads to the path-independent feature of the mapping, e.g. multi-time evolution in the Schrödinger picture. Another important result is the formulation of the continuous multi-time propagator. With this new type of the propagator, a new perspective on summing all possible paths unavoidably arises as not only all possible paths in the space of dependent variables but also in the space of independent variables must be taken into account. The semi-classical approximation is applied to the multi-time propagator expressing in terms of the classical action and the fluctuation around it. Therefore, the extremum propagator, resulting in path independent feature on the space of independent variables, would guarantee the integrability of the system.

math-ph↗