• Title/Summary/Keyword: hamiltonian

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Investigating Exoplanet Orbital Evolution Around Binary Star Systems with Mass Loss

  • Rahoma, Walid A.
    • Journal of Astronomy and Space Sciences
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    • v.33 no.4
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    • pp.257-264
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    • 2016
  • A planet revolving around binary star system is a familiar system. Studies of these systems are important because they provide precise knowledge of planet formation and orbit evolution. In this study, a method to determine the evolution of an exoplanet revolving around a binary star system using different rates of stellar mass loss will be introduced. Using a hierarchical triple body system, in which the outer body can be moved with the center of mass of the inner binary star as a two-body problem, the long period evolution of the exoplanet orbit is determined depending on a Hamiltonian formulation. The model is simulated by numerical integrations of the Hamiltonian equations for the system over a long time. As a conclusion, the behavior of the planet orbital elements is quite affected by the rate of the mass loss from the accompanying binary star.

Generation of Finite Inductive, Pseudo Random, Binary Sequences

  • Fisher, Paul;Aljohani, Nawaf;Baek, Jinsuk
    • Journal of Information Processing Systems
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    • v.13 no.6
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    • pp.1554-1574
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    • 2017
  • This paper introduces a new type of determining factor for Pseudo Random Strings (PRS). This classification depends upon a mathematical property called Finite Induction (FI). FI is similar to a Markov Model in that it presents a model of the sequence under consideration and determines the generating rules for this sequence. If these rules obey certain criteria, then we call the sequence generating these rules FI a PRS. We also consider the relationship of these kinds of PRS's to Good/deBruijn graphs and Linear Feedback Shift Registers (LFSR). We show that binary sequences from these special graphs have the FI property. We also show how such FI PRS's can be generated without consideration of the Hamiltonian cycles of the Good/deBruijn graphs. The FI PRS's also have maximum Shannon entropy, while sequences from LFSR's do not, nor are such sequences FI random.

Dipole Moments of the OH, OH$^+$, and OH$^-$Valence States by ab initio Effective Valence Shell Hamiltonian Method

  • Sun, Ho-Sung
    • Bulletin of the Korean Chemical Society
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    • v.9 no.2
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    • pp.101-105
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    • 1988
  • The ab initio effective valence shell Hamiltonian method, based on quasidegenerate many-body perturbation theory, is generalized to calculate molecular properties as well as the valence state energies which have previously been determined for atoms and small molecules. The procedure requires the evaluation of effective operator for each molecular property. Effective operators are perturbatively expanded in powers of correlation and contain contributions from excitations outside of the multireference valence space. To demonstrate the validity of this method, calculations for dipole moments of several low lying valence states of OH, $OH^+$, and $OH^-$ to first order in the correlations have been performed and compared with configuration interaction calculations.

The Gauge Invariant Formulation for the Interaction of the Quantized Radiation Field with Matter

  • 이덕환
    • Bulletin of the Korean Chemical Society
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    • v.20 no.6
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    • pp.720-726
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    • 1999
  • It has been proved by the semi-classical gauge invariant formulation (GIF) that the correct interaction operator for coupling the field-free material states with the radiation field must be the position form regardless of the gauge chosen for expressing the electromagnetic potentials, in accordance with the well-established principle of gauge invariance. The semi-classical GIF is now extended to the quantized radiation field interacting with matter by defining the energy operator for the quantized radiation field in the presence of matter. It will be shown in this paper that the use of the energy operator guarantees the position form of the interaction operator even in the Coulomb gauge, contrary to the conventional approach in which the dark material Hamiltonian is used to get the interaction operator of the momentum form. The multipolar Hamiltonian is examined in the context of the quantum mechanical gauge transformation.

The Potential Energy Surfaces and Dipole Moment Functions of $NH_2$ by ab initio Effective Valence Shell Hamiltonian

  • 윤승훈;윤영속;박종근;선호성
    • Bulletin of the Korean Chemical Society
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    • v.19 no.9
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    • pp.985-993
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    • 1998
  • The second order effective valence shell Hamiltonian ($H^v$), which is based on quasidegencrate many-body perturbation theory, is applied to determining the potential energy surfaces and the dipole moment functions of the various valence states of $NH_2$. The $H^v$ calculated values are found to be in good agreement with those of other ab initio calculations or experiments. It signifies the fact that the $H^v$ is a good ab initio method to describe the energies and properties of various valence states with a same chemical accuracy. Furthermore, it is shown that the lowest (second order for energy and the first order for property) order $H^v$ method is very accurate for small molecules like $NH_2$ and the matrix elements of Hv which are computed only once are all we need to accurately describe all the valence states simultaneously.

Ab initio Effective Hamiltonian Calculations on the Valence States of SiH, $SiH^+$, PH and $PH^+$

  • Park Jong Keun;Sun Hosung
    • Bulletin of the Korean Chemical Society
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    • v.13 no.4
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    • pp.429-440
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    • 1992
  • The second order ab initio effective valence shall Hamiltonian ($H^v$) which is based on quasidegenerate many-body perturbation theory is applied to the SiH, PH, and their positive ions. A singie Hv computation for the neutral molecule is used for a whole set of valence states of a molecule and its ion simultaneously. The low-lying valence state potential energy curves of SiH, PH and their positive ions are computed. And various spectroscopic constants of the low-lying bound valence states are determined from the potential energy curves. The $H^v$ results are found to be in good agreement with other theoretical and experimental data.

Nonlinear vibration and stability of FG nanotubes conveying fluid via nonlocal strain gradient theory

  • Dang, Van-Hieu;Sedighi, Hamid M.;Chan, Do Quang;Civalek, Omer;Abouelregal, Ahmed E.
    • Structural Engineering and Mechanics
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    • v.78 no.1
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    • pp.103-116
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    • 2021
  • In this work, a model of a functionally graded (FG) nanotube conveying fluid embedded in an elastic medium is developed based on the nonlocal strain gradient theory (NSGT) in conjunction with Euler-Bernoulli beam theory (EBT). The main objective of this research is to investigate the nonlinear vibration and stability analysis of fluid-conveying nanotubes. The governing equations of motion are derived by means of Hamiltonian principle. The analytical expressions of nonlinear frequencies and critical flow velocities for two different types of boundary conditions including pinned-pinned (P-P) and clamped-clamped (C-C) conditions are obtained by employing Galerkin method as well as Hamiltonian Approach (HA). Comparison of the obtained results with the published works show the acceptable accuracy of the current solutions. The effects of the power-law index, the nonlocal and material length scale parameters and the elastic medium on the stability and nonlinear responses of FG nanotubes are thoroughly investigated and discussed.

Energy and Temperature Dependences of the Spin Cutoff Parameter in 50-57Cr Isotopes

  • Razavi, R.;Mohassel, A. Rashed;Rahmatinejad, A.;Mohammadi, S.
    • Journal of the Korean Physical Society
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    • v.73 no.10
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    • pp.1550-1554
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    • 2018
  • The spin cutoff parameters of $^{50-57}Cr$ isotopes have been calculated using a superconducting Hamiltonian with the inclusion of the pairing effect. Their energy and temperature dependences have been studied through comparison with some well-known semi-empirical formulae. This study shows that the microscopic calculation results converge to the Fermi gas model prediction at higher energies. Also, an even-odd effect is evident in the spin cutoff parameters at low temperatures and disappears after the pairing phase transition.

A Survey of Public-Key Cryptography over Non-Abelian Groups

  • Lanel, G.H.J.;Jinasena, T.M.K.K.;Welihinda, B.A.K.
    • International Journal of Computer Science & Network Security
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    • v.21 no.4
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    • pp.289-300
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    • 2021
  • Non-abelian group based Cryptography is a field which has become a latest trend in research due to increasing vulnerabilities associated with the abelian group based cryptosystems which are in use at present and the interesting algebraic properties associated that can be thought to provide higher security. When developing cryptographic primitives based on non-abelian groups, the researchers have tried to extend the similar layouts associated with the traditional underlying mathematical problems and assumptions by almost mimicking their operations which is fascinating even to observe. This survey contributes in highlighting the different analogous extensions of traditional assumptions presented by various authors and a set of open problems. Further, suggestions to apply the Hamiltonian Cycle/Path Problem in a similar direction is presented.

ON TORIC HAMILTONIAN T-SPACES WITH ANTI-SYMPLECTIC INVOLUTIONS

  • Kim, Jin Hong
    • Bulletin of the Korean Mathematical Society
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    • v.59 no.3
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    • pp.671-683
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    • 2022
  • The aim of this paper is to deal with the realization problem of a given Lagrangian submanifold of a symplectic manifold as the fixed point set of an anti-symplectic involution. To be more precise, let (X, ω, µ) be a toric Hamiltonian T-space, and let ∆ = µ(X) denote the moment polytope. Let τ be an anti-symplectic involution of X such that τ maps the fibers of µ to (possibly different) fibers of µ, and let p0 be a point in the interior of ∆. If the toric fiber µ-1(p0) is real Lagrangian with respect to τ, then we show that p0 should be the origin and, furthermore, ∆ should be centrally symmetric.