4 papers
A note on the extended dToda hierarchy
Niann-Chern Lee, Ming-Hsien Tu
We give a derivation of dispersionless Hirota equations for the extended dispersionless Toda hierarchy. We show that the dispersionless Hirota equations are nothing but a direct co…
Kernel Formula Approach to the Universal Whitham Hierarchy
Hsin-Fu Shen, Niann-Chern Lee, Ming-Hsien Tu
We derive the dispersionless Hirota equations of the universal Whitham hierarchy from the kernel formula approach proposed by Carroll and Kodama. Besides, we also verify the associ…
A Note on Symmetries of WDVV Equations
Yu-Tung Chen, Niann-Chern Lee, Ming-Hsien Tu
We investigate symmetries of Witten-Dijkgraaf-E.Verlinde-H.Verlinde (WDVV) equations proposed by Dubrovin from bi-hamiltonian point of view. These symmetries can be viewed as canon…
Conformal Covariantization of Moyal-Lax Operators
Ming-Hsien Tu, Niann-Chern Lee, Yu-Tung Chen
A covariant approach to the conformal property associated with Moyal-Lax operators is given. By identifying the conformal covariance with the second Gelfand-Dickey flow, we covaria…