293,849 research outputs found

    Higher Toda Mechanics and Spectral Curves

    Full text link
    For each one of the Lie algebras gln\mathfrak{gl}_{n} and gl~n\widetilde {\mathfrak{gl}}_{n}, we constructed a family of integrable generalizations of the Toda chains characterized by two integers m+m_{+} and mm_{-}. The Lax matrices and the equations of motion are given explicitly, and the integrals of motion can be calculated in terms of the trace of powers of the Lax matrix LL. For the case of m+=mm_{+}=m_{-}, we find a symmetric reduction for each generalized Toda chain we found, and the solution to the initial value problems of the reduced systems is outlined. We also studied the spectral curves of the periodic (m+,m)(m_{+},m_{-})-Toda chains, which turns out to be very different for different pairs of m+m_{+} and mm_{-}. Finally we also obtained the nonabelian generalizations of the (m+,m)(m_{+},m_{-})-Toda chains in explicit form.Comment: 22 page

    Generalized Toda mechanics associated with classical Lie algebras and their reductions

    Full text link
    For any classical Lie algebra gg, we construct a family of integrable generalizations of Toda mechanics labeled a pair of ordered integers (m,n)(m,n). The universal form of the Lax pair, equations of motion, Hamiltonian as well as Poisson brackets are provided, and explicit examples for g=Br,Cr,Dr\mathfrak{g}=B_{r},C_{r},D_{r} with m,n3m,n\leq3 are also given. For all m,nm,n, it is shown that the dynamics of the (m,n1)(m,n-1)- and the (m1,n)(m-1,n)-Toda chains are natural reductions of that of the (m,n)(m,n)-chain, and for m=nm=n, there is also a family of symmetrically reduced Toda systems, the (m,m)Sym(m,m)_{\mathrm{Sym}}-Toda systems, which are also integrable. In the quantum case, all (m,n)(m,n)-Toda systems with m>1m>1 or n>1n>1 describe the dynamics of standard Toda variables coupled to noncommutative variables. Except for the symmetrically reduced cases, the integrability for all (m,n)(m,n)-Toda systems survive after quantization.Comment: 19 pages, bibte

    Distributed Flow Scheduling in an Unknown Environment

    Full text link
    Flow scheduling tends to be one of the oldest and most stubborn problems in networking. It becomes more crucial in the next generation network, due to fast changing link states and tremendous cost to explore the global structure. In such situation, distributed algorithms often dominate. In this paper, we design a distributed virtual game to solve the flow scheduling problem and then generalize it to situations of unknown environment, where online learning schemes are utilized. In the virtual game, we use incentives to stimulate selfish users to reach a Nash Equilibrium Point which is valid based on the analysis of the `Price of Anarchy'. In the unknown-environment generalization, our ultimate goal is the minimization of cost in the long run. In order to achieve balance between exploration of routing cost and exploitation based on limited information, we model this problem based on Multi-armed Bandit Scenario and combined newly proposed DSEE with the virtual game design. Armed with these powerful tools, we find a totally distributed algorithm to ensure the logarithmic growing of regret with time, which is optimum in classic Multi-armed Bandit Problem. Theoretical proof and simulation results both affirm this claim. To our knowledge, this is the first research to combine multi-armed bandit with distributed flow scheduling.Comment: 10 pages, 3 figures, conferenc