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We present numerical solutions to the extended Doering-Constantin variational principle for upper bounds on the energy dissipation rate in turbulent plane Couette flow. Using the compound matrix technique in order to reformulate this…

Soft Condensed Matter · Physics 2009-10-31 Rolf Nicodemus , Siegfried Grossmann , Martin Holthaus

We develop a variational method to obtain accurate bounds for the eigenenergies of H = -Delta + V in arbitrary dimensions N>1, where V(r) is the nonpolynomial oscillator potential V(r) = r^2 + lambda r^2/(1+gr^2), lambda in…

Mathematical Physics · Physics 2009-11-11 Nasser Saad , Richard L. Hall , Hakan Ciftci

Solving non-Hermitian quantum many-body systems on a quantum computer by minimizing the variational energy is challenging as the energy can be complex. Here, based on energy variance, we propose a variational method for solving the…

Quantum Physics · Physics 2024-02-21 Xu-Dan Xie , Zheng-Yuan Xue , Dan-Bo Zhang

The three-dimensional nonlinear dynamics of an electron gas in a semiconductor quantum well is analyzed in terms of a self-consistent fluid formulation and a variational approach. Assuming a time-dependent localized profile for the fluid…

Plasma Physics · Physics 2015-06-05 F. Haas

The quantum mechanical many-body problem is rarely analytically solvable. One notable exception is the case of two electrons interacting via a Coulomb potential in a uniform magnetic field. The motion is confined to a two-dimensional plane,…

Mesoscale and Nanoscale Physics · Physics 2011-01-04 Tobias Kramer

Recently, the class of energy-conserving Runge-Kutta methods named Hamiltonian Boundary Value Methods (HBVMs), has been proposed for the efficient solution of Hamiltonian problems, as well as for other types of conservative problems. In…

Numerical Analysis · Mathematics 2013-10-22 Luigi Brugnano , Yajuan Sun

We consider the problem of estimating the energy of a quantum state preparation for a given Hamiltonian in Pauli decomposition. For various quantum algorithms, in particular in the context of quantum chemistry, it is crucial to have energy…

Quantum Physics · Physics 2025-08-20 Alexander Gresch , Uğur Tepe , Martin Kliesch

A variational method is used to derive a self-consistent macro-particle model for relativistic electromagnetic kinetic plasma simulations. Extending earlier work [E. G. Evstatiev and B. A. Shadwick, J. Comput. Phys., vol. 245, pp. 376-398,…

Computational Physics · Physics 2014-04-22 A. B. Stamm , B. A. Shadwick , E. G. Evstatiev

By variational Monte-Carlo method developed Ceperley et al. for the simulation of fermi systems in macroscopic confining potential well we simulate various spin ground states of the coulomb clusters with 2,3 and 4 particles in a broad…

Condensed Matter · Physics 2007-05-23 B. Abdullaev , A. D. Kidisyuk , M. M. Musakhanov

A new theoretical method is developed to solve the two-body bound-state Dirac equation for positronium. Only Coulomb potential was included in the Dirac Hamiltonian. It is shown that the two-body Dirac Hamiltonian can be written in the…

High Energy Physics - Phenomenology · Physics 2024-06-11 E. M. Tursunov , Sh. G. Norbutaev , B. A. Fayzullaev

The congruent transformation of the electronic Hamiltonian is developed to address the electron correlation problem in many-electron systems. The central strategy presented in this method is to perform transformation on the electronic…

Chemical Physics · Physics 2012-12-21 Jennifer M. Elward , Johannes Hoja , Arindam Chakraborty

We use a variational method to construct soliton solutions for systems characterized by opposing dispersion and competing nonlinearities at fundamental and second harmonics. We show that both ordinary and embedded solitons tend to gain…

Exactly Solvable and Integrable Systems · Physics 2007-06-06 Debabrata Pal , Sk. Golam Ali , B. Talukdar

We are concerned with the problem of decomposing the parameter space of a parametric system of polynomial equations, and possibly some polynomial inequality constraints, with respect to the number of real solutions that the system attains.…

Symbolic Computation · Computer Science 2022-02-11 AmirHosein Sadeghimanesh , Matthew England

A computational method is proposed to calculate bound and resonant states by solving the Klein-Gordon and Dirac equations for real and complex energies, respectively. The method is an extension of a non-relativistic one, where the potential…

Quantum Physics · Physics 2023-12-06 D. Wingard , B. Kónya , Z. Papp

Bound states of hyperbolic potential is investigated by means of a generalized pseudospectral method. Significantly improved eigenvalues, eigenfunctions are obtained efficiently for arbitrary $n, \ell$ quantum states by solving the relevant…

Chemical Physics · Physics 2015-06-22 Amlan K. Roy

Energies of the low-lying bound S-states (L=0) of exotic three-body systems, consisting a nuclear core of charge +Ze (Z being atomic number of the core) and two negatively charged valence muons, have been calculated by hyperspherical…

Atomic Physics · Physics 2015-11-19 Md. Abdul Khan

Bohr's model agreed with the hydrogen spectrum results, but did not agree with the spectrum of Helium. Here we show that Bohr's model-based methods can calculate the experimental value (-79.005 eV) of Helium ground state energy correctly.…

Computational Physics · Physics 2009-03-17 Youhei Tsubono

We investigate Monte Carlo energy and variance minimization techniques for optimizing many-body wave functions. Several variants of the basic techniques are studied, including limiting the variations in the weighting factors which arise in…

Condensed Matter · Physics 2009-10-31 P. R. C. Kent , R. J. Needs , G. Rajagopal

Variational perturbation theory is used to determine the decay rates of metastable states across a cubic barrier of arbitrary height. For high barriers, a variational resummation procedure is applied to the complex energy eigenvalues…

Quantum Physics · Physics 2016-08-15 H. Kleinert , I. Mustapic

In the variational principle leading to the Euler equation for a perfect fluid, we can use the method of undetermined multiplier for holonomic constraints representing mass conservation and adiabatic condition. For a dissipative fluid, the…

Fluid Dynamics · Physics 2012-06-03 Hiroki Fukagawa , Youhei Fujitani