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This report shows how insights gained from system dynamics modeling and the U.S. STEM Undergraduate Model® can help inform the Navy's strategy to grow a robust civilian workforce that is strongly invested with Navy-relevant STEM skills and ready to contribute to the next generation of Naval innovation. This work positions the Navy to serve a strong national leadership role in advancing President Obama's goals in STEM precisely while it enhances Naval STEM capacity. That powerful synergy is doing much to advance important improvements in the shaping and execution of the STEM education pathway.

This report shows how insights gained from system dynamics modeling and the U.S. STEM Undergraduate Model® can help inform the Navy's strategy to grow a robust civilian workforce that is strongly invested with Navy-relevant STEM skills and ready to contribute to the next generation of Naval innovation. This work positions the Navy to serve a strong national leadership role in advancing President Obama's goals in STEM precisely while it enhances Naval STEM capacity. That powerful synergy is doing much to advance important improvements in the shaping and execution of the STEM education pathway.

This report shows how insights gained from system dynamics modeling and the U.S. STEM Undergraduate Model® can help inform the Navy's strategy to grow a robust civilian workforce that is strongly invested with Navy-relevant STEM skills and ready to contribute to the next generation of Naval innovation. This work positions the Navy to serve a strong national leadership role in advancing President Obama's goals in STEM precisely while it enhances Naval STEM capacity. That powerful synergy is doing much to advance important improvements in the shaping and execution of the STEM education pathway.

Structural Research Capability Database of HBCUs was developed which can be used to recall data about HBCU faculty capabilities and research interests, and university research facilities. The records are focused toward Flight Dynamics Directorate research and technology needs and should facilitate and increase faculty and student participation in the Flight Dynamics Directorate research programs by familiarizing Flight Dynamics Directorate in- house researchers with those at the cited HBCUS. Additional records may be appended to the database. More data were obtained than was contemplated, some universities provided brochures and other additional published data. This report serves as a user's guide for the database program.

The ppK^- system, as a prototype for possible quasibound Kbar nuclei,is investigated using a variational approach. Several versions of energy dependent effective KbarN interactions derived from chiral SU(3) dynamics are employed as input, together with a realistic NN potential (Av18). Taking into account theoretical uncertainties in the extrapolations below the KbarN threshold, we find that the antikaonic dibaryon ppK^- is NOT deeply bound. With the driving s-wave KbarN interaction the resulting total binding energy is B(ppK^-) = 20 $\pm$ 3 MeV and the mesonic decay width involving KbarN -> \pi Y is expected to be in the range 40 - 70 MeV. Properties of this quasibound ppK^- system (such as density distributions of nucleons and antikaon) are discussed. The \Lambda(1405), as an I=0 quasi-bound state of Kbar and a nucleon, appears to survive in the ppK^- cluster. Estimates are given for the influence of p-wave KbarN interactions and for the width from two-nucleon absorption (KbarNN -> YN) processes. With inclusionof these effects and dispersive corrections from absorption, the ppK^- binding energy is expected to be in the range 20 - 40 MeV, while the total decay width can reach 100 MeV but with large theoretical uncertainties.

In this paper, we study the global in time existence problem for the Groma-Balogh model describing the dynamics of dislocation densities. This model is a two-dimensional model where the dislocation densities satisfy a system of transport equations such that the velocity vector field is the shear stress in the material, solving the equations of elasticity. This shear stress can be expressed as some Riesz transform of the dislocation densities. The main tool in the proof of this result is the existence of an entropy for this system

In this paper, we study the global in time existence problem for the Groma-Balogh model describing the dynamics of dislocation densities. This model is a two-dimensional model where the dislocation densities satisfy a system of transport equations such that the velocity vector field is the shear stress in the material, solving the equations of elasticity. This shear stress can be expressed as some Riesz transform of the dislocation densities. The main tool in the proof of this result is the existence of an entropy for this system

In this paper, we study the global in time existence problem for the Groma-Balogh model describing the dynamics of dislocation densities. This model is a two-dimensional model where the dislocation densities satisfy a system of transport equations such that the velocity vector field is the shear stress in the material, solving the equations of elasticity. This shear stress can be expressed as some Riesz transform of the dislocation densities. The main tool in the proof of this result is the existence of an entropy for this system

Recent observation of microlensing technique reveals two giant planets at 2.3 AU and 4.6 AU around the star OGLE-06-109L. The eccentricity of the outer planet (ec) is estimated to be 0.11(+0.17,-0.04), comparable to that of Saturn (0.01-0.09). The similarities between the OGLE-06-109L system and the solar system indicate that they may have passed through similar histories during their formation stage. In this paper we investigate the dynamics and formation of the orbital architecture in the OGLE-06-109L system. For the present two planets with their nominal locations, the secular motions are stable as long as their eccentricities (eb; ec) fulfill eb^2 + ec^2 < = 0.3^2. Earth-size bodies might be formed and are stable in the habitable zone (0.25AU-0.36AU) of the system. Three possible scenarios may be accounted for formation of eb and ec: (i) convergent migration of two planets and the 3:1 MMR trapping; (ii) planetary scattering; (iii) divergent migration and the 3:1 MMR crossing. As we showed that the probability for the two giant planets in 3:1 MMR is low (~3%), scenario (i) is less likely. According to models (ii) and (iii), the final eccentricity of inner planet (eb) may oscillate between [0-0.06], comparable to that of Jupiter (0.03-0.06). An inspection of eb, ec secular motion may be helpful to understand which model is really responsible for the eccentricity formation.

We fully characterize the reduced dynamics of an open quantum system initially correlated with its environment. Using a photonic qubit coupled to a simulated environment we tomographically reconstruct a superchannel---a generalised channel that treats preparation procedures as inputs---from measurement of the system alone, despite its coupling to the environment. We introduce novel quantitative measures for determining the strength of initial correlations, and to allow an experiment to be optimised in regards to its environment.

We look at the high-lying eigenstates (from the 10,001st to the 13,000th) in the Robnik billiard (defined as a quadratic conformal map of the unit disk) with the shape parameter $\lambda=0.15$. All the 3,000 eigenstates have been numerically calculated and examined in the configuration space and in the phase space which - in comparison with the classical phase space - enabled a clear cut classification of energy levels into regular and irregular. This is the first successful separation of energy levels based on purely dynamical rather than special geometrical symmetry properties. We calculate the fractional measure of regular levels as $\rho_1=0.365\pm 0.01$ which is in remarkable agreement with the classical estimate $\rho_1=0.360\pm 0.001$. This finding confirms the Percival's (1973) classification scheme, the assumption in Berry-Robnik (1984) theory and the rigorous result by Lazutkin (1981,1991). The regular levels obey the Poissonian statistics quite well whereas the irregular sequence exhibits the fractional power law level repulsion and globally Brody-like statistics with $\beta = 0.286\pm0.001$. This is due to the strong localization of irregular eigenstates in the classically chaotic regions. Therefore in the entire spectrum we see that the Berry-Robnik regime is not yet fully established so that the level spacing distribution is correctly captured by the Berry-Robnik-Brody distribution (Prosen and Robnik 1994).

Advances in healthcare and in the quality of life significantly increase human life expectancy. With the ageing of populations, new un-faced challenges are brought to science. The human body is naturally selected to be well-functioning until the age of reproduction to keep the species alive. However, as the lifespan extends, unseen problems due to the body deterioration emerge. There are several age-related diseases with no appropriate treatment; therefore, the complex ageing phenomena needs further understanding. Immunosenescence, the ageing of the immune system, is highly correlated to the negative effects of ageing, such as the increase of auto-inflammatory diseases and decrease in responsiveness to new diseases. Besides clinical and mathematical tools, we believe there is opportunity to further exploit simulation tools to understand immunosenescence. Compared to real-world experimentation, benefits include time and cost effectiveness due to the laborious, resource-intensiveness of the biological environment and the possibility of conducting experiments without ethic restrictions. Contrasted with mathematical models, simulation modelling is more suitable for representing complex systems and emergence. In addition, there is the belief that simulation models are easier to communicate in interdisciplinary contexts. Our work investigates the usefulness of simulations to understand immunosenescence by employing two different simulation methods, agent-based and system dynamics simulation, to a case study of immune cells depletion with age.

We report the reflectivity and the resistivity measurement of Ca_{2-x}Na_{x}CuO_{2}Cl_{2} (CNCOC), which has a single-CuO2-plane lattice with no orthorhombic distortion. The doping dependence of the in-plane optical conductivity spectra for CNCOC is qualitatively the same to those of other cuprates, but a slight difference between CNCOC and LSCO, i.e., the absence of the 1.5 eV peak in CNCOC, can be attributed to the smaller charge-stripe instability in CNCOC. The temperature dependence of the optical onductivity spectra of CNCOC has been analyzed both by the two-component model (Drude+Lorentzian) and by the one-component model (extended-Drude analysis). The latter analysis gives a universal trend of the scattering rate Gamma(omega) with doping. It was also found that Gamma(omega) shows a saturation behavior at high frequencies, whose origin is the same as that of resistivity saturation at high temperatures.

We provide analytic solutions of the optical Bloch equations for a two-level system interacting with a broadband light field. We will focus on two special examples: incident light with a Lorentzian spectral density and the limit of incident monochromatic light. The results are used to obtain an expression for the nonlinear polarizability of a two-level atom irradiated by a wave with a Lorentzian spectral density.

We study the dynamics of a two-level system described by a slowly varying Hamiltonian and weakly coupled to the Ohmic environment. We follow the Bloch--Redfield perturbative approach to include the effect of the environment on qubit evolution and take into account modification of the spectrum and matrix elements of qubit transitions due to time-dependence of the Hamiltonian. This formalism is applied to two problems. (1) We consider a qubit, or a spin-1/2, in a rotating magnetic field. We show that once the rotation starts, the spin has a component perpendicular to the rotation plane of the field that initially wiggles and eventually settles to the value proportional to the product of angular rotation velocity of the field and the Berry curvature. (2) We re-examine the Landau--Zener transition for a system coupled to environment at arbitrary temperature. We show that as temperature increases, the thermal excitation and relaxation become leading processes responsible for transition between states of the system. We also apply the Lindblad master equations to these two problems and compare results with those obtained from the Bloch--Redfield equations.

We consider the dynamics of the stochastic shadow Gierer-Meinhardt system with one-dimensional standard Brownian motion. We establish the global existence and uniqueness of solutions. We also prove a large deviation result.

We consider the dynamics of the stochastic shadow Gierer-Meinhardt system with one-dimensional standard Brownian motion. We establish the global existence and uniqueness of solutions. We also prove a large deviation result.

A molecular dynamics simulation is performed to investigate spatial scale of low energy excitation (LEE) in a single linear chain of united atoms. The self part of the dynamic structure function, $S_\mathrm{S}(q,\omega)$, is obtained in a wide range in frequency space ($\omega$) and reciprocal space ($q$). A broad peak corresponding to the LEE is detected at $\omega/2\pi=2.5 \times 10^{11} \mathrm{s^{-1}}$ ($\equiv \omega_{\mathrm{LEE}}/2\pi$) on the contour maps of $S_\mathrm{S}(q,\omega)$, near and below the glass transition temperature ($T_{\mathrm{g}}$=230 K). The $S_\mathrm{S}(q,\omega_{\mathrm{LEE}})$ is symmetric around a maximum along the logarithm of $q$. The inverse of $q_{\mathrm{max}}$, giving the maximum position of $S_\mathrm{S}(q,\omega_{\mathrm{LEE}})$, depends on temperature as $2\pi/q_{\mathrm{max}}\sim T^{0.52}$ for $60 \mathrm{K}

We discuss recent results obtained for the Hamiltonian Mean Field model. The model describes a system of N fully-coupled particles in one dimension and shows a second-order phase transition from a clustered phase to a homogeneous one when the energy is increased. Strong chaos is found in correspondence to the critical point on top of a weak chaotic regime which characterizes the motion at low energies. For a small region around the critical point, we find anomalous (enhanced) diffusion and L\'evy walks in a transient temporal regime before the system relaxes to equilibrium.

Currently, student research at the university under study is carried out from the first semesters until the student graduates, but it is necessary to make adjustments to its guidelines that include student research within a teaching-learning process. The objective of the research is to propose a model of student research, using causal diagrams and forrester diagram; then carry out a simulation of the projection from 2021 to 2026 with the variables, students, quality teachers in the research, completed work for publication in journal or conference; and thus index in Scopus or Web of Science. Besides, in the methodological part, the systems dynamics method was applied, based on the systemic approach. The research work is predictive, which was carried out with the Vensim software, obtaining as a result of the simulation, an increase in the production of complete Works by the students; where in 2026 around 300 articles will be published by the students. In addition, there will be about 12 full-time quality research professors and approximately 6,000 students in 2026. The conclusion reached in the research is that the model helps the authorities make decisions appropriately according to the forecasts made in the different scenarios made with the Vensim software.

Bibliography: leaves 83-85

Bibliography: leaves 83-85

Asylum and refugees in Europe – who can fix a broken system? In times of increasing waves of migration, collective bodies and their cooperation networks are of particular importance to the European asylum system. But who are those actors and what is their contribution to effecting a change in the situation of those seeking refuge in Europe? While the Common European Asylum System introduced standardised regulations for all EU-member states, the real situation in each country differs greatly from those official declarations, even leading to a humanitarian crisis at times. Using the theory of neo-institutionalism, current data from expert interviews, and website and document analyses from Italy, Spain, Greece, Cyprus, Malta and Germany, this study answers those questions. It illustrates how and if this gap between talk and action can be narrowed, how asylum-related organisations and their networks function and how far they contribute to this process. With contributions by: Remonda Balje, Alexander Bauhus, Charlotte Becker-Jamme, Tobias Breuckmann, Megan Costello, Amanda Culver, Dea Dhima, Giselaldina Duro, Lara Elliott, Thomas Hoppe, Lana Horsthemke, Timo Kemp, Jana Komorowski, Melisa Lehmann, Stefan Letmathe, Alona Mirko, Anna Mratschkowski, Judith Nitsche, Thomas Norpoth, Jakob Reckers, Elodie Scholten, Mats Schulte, Davide Scotti, Sara Stojani, Friederike Vogt, Julia Werner, Gerrit Zumstein

In this paper, we study entanglement dynamics of a two-qubit extended Werner-like state locally interacting with independent noisy channels, i.e., amplitude damping, phase damping and depolarizing channels. We show that the purity of initial entangled state has direct impacts on the entanglement robustness in each noisy channel. That is, if the initial entangled state is prepared in mixed instead of pure form, the state may exhibit entanglement sudden death (ESD) and/or be decreased for the critical probability at which the entanglement disappear.

The dissipative dynamics of a two-qubit system is studied theoretically. We make use of the Bloch-Redfield formalism which explicitly includes the parameter-dependent relaxation rates. We consider the case of two flux qubits, when the controlling parameters are the partial magnetic fluxes through the qubits' loops. The strong dependence of the inter-level relaxation rates on the controlling magnetic fluxes is demonstrated for the realistic system. This allows us to propose several mechanisms for lasing in this four-level system.

The dissipative dynamics of a two-qubit system is studied theoretically. We make use of the Bloch-Redfield formalism which explicitly includes the parameter-dependent relaxation rates. We consider the case of two flux qubits, when the controlling parameters are the partial magnetic fluxes through the qubits' loops. The strong dependence of the inter-level relaxation rates on the controlling magnetic fluxes is demonstrated for the realistic system. This allows us to propose several mechanisms for lasing in this four-level system.

In this paper a four-dimensional hyperchaotic system with only one equilibrium is considered and its double Hopf bifurcations are investigated. The general post-bifurcation and stability analysis are carried out using the normal form of the system obtained via the method of multiple scales. The dynamics of the orbits predicted through the normal form comprises possible regimes of periodic solutions, two-period tori, and three-period tori in parameter space. Moreover, we show how the hyperchaotic synchronization of this system can be realized via an adaptive control scheme. Numerical simulations are included to show the effectiveness of the designed control.

Entanglement dynamics of a qutrit-qutrit system under the influence of global, local and multilocal decoherence introduced by phase flip, trit flip and trit phase flip channels is investigated. The negativity and realignment criterion are used to quantify the entanglement of the system. It is shown that the entanglement sudden death and distibility sudden death can be avoided in the presence of phase flip, trit flip and trit-phase flip environments. It is shown that certain free entangled distillable qutrit states become bound entangled or separable i.e. convert into non-distillable states under different flipping noises. It is also seen that local operations do not have any effect on the entanglement dynamics of the system. Further more, no ESD and DSD is seen for the case of trit flip channel.

Pursuing our work in [18], [17], [20], [5], we consider in this article the two-dimensional thermohydraulics equations. We discretize these equations in time using the implicit Euler scheme and we prove that the global attractors generated by the numerical scheme converge to the global attractor of the continuous system as the time-step approaches zero.

The system-environment dynamics of noninertial systems is investigated. It is shown that for the amplitude damping channel: (i) the biggest difference between the decoherence effect and the Unruh radiation on the dynamics of the entanglement is the former only leads to entanglement transfer in the whole system, but the latter damages all types of entanglement; (ii) the system-environment entanglement increases and then declines, while the environment-environment entanglement always increases as the decay parameter $p$ increases; and (iii) the thermal fields generated by the Unruh effect can promote the sudden death of entanglement between the subsystems while postpone the sudden birth of entanglement between the environments. It is also found that there is no system-environment and environment-environment entanglements when the system coupled with the phase damping environment.

We study the non-adiabatic dynamics of a two-state subsystem in a bath of independent spins using the non-interacting blip approximation, and derive an exact analytic expression for the relevant memory kernel. We show that in the thermodynamic limit, when the subsystem-bath coupling is diluted (uniformly) over many (infinite) degrees of freedom, our expression reduces to known results, corresponding to the harmonic bath with an effective, temperature-dependent, spectral density function. We then proceed and study the heat current characteristics in the out-of-equilibrium spin-spin-bath model, with a two-state subsystem bridging two thermal spin-baths of different temperatures. We compare the behavior of this model to the case of a spin connecting boson baths, and demonstrate pronounced qualitative differences between the two models. Specifically, we focus on the development of the thermal diode effect, and show that the spin-spin-bath model cannot support it at weak (subsystem-bath) coupling, while in the intermediate-strong coupling regime its rectifying performance outplays the spin-boson model.

The effect of decoherence on a qubit-qutrit system under the influence of global and multilocal decoherence in non-inertial frames is investigated. It is shown that the entanglement sudden death (ESD) can be avoided in non-inertial frames in the presence of dephasing and bit-trit phase flip channels for entire range of decoherence. However, ESD behaviour is seen for higher level of decoherence in case of phase flip and bit-trit flip channels. Irrespective of the entanglement degradation caused by the Unruh effect, no ESD occurs for the dephasing environment. Furthermore, flipping channels have approximately similar effect on the entanglement of the hybrid system.

We present a numerical path-integral iteration scheme for the low dimensional reduced density matrix of a time-dependent quantum dissipative system. Our approach simultaneously accounts for the combined action of a microscopically modelled pure-dephasing type coupling to a continuum of harmonic oscillators representing, e.g., phonons, and further environmental interactions inducing non-Hamiltonian dynamics in the inner system represented, e.g., by Lindblad type dissipation or relaxation. Our formulation of the path-integral method allows for a numerically exact treatment of the coupling to the oscillator modes and moreover is general enough to provide a natural way to include Markovian processes that are sufficiently described by rate equations. We apply this new formalism to a model of a single semiconductor quantum dot which includes the coupling to longitudinal acoustic phonons for two cases: a) external laser excitation taking into account a phenomenological radiative decay of the excited dot state and b) a coupling of the quantum dot to a single mode of an optical cavity taking into account cavity photon losses.

Recent experiments on quantum behavior in microfabricated solid-state systems suggest tantalizing connections to quantum optics. Several of these experiments address the prototypical problem of cavity quantum electrodynamics: a two-level system coupled to a quantum harmonic oscillator. Such devices may allow the exploration of parameter regimes outside the near-resonance and weak-coupling assumptions of the ubiquitous rotating-wave approximation (RWA), necessitating other theoretical approaches. One such approach is an adiabatic approximation in the limit that the oscillator frequency is much larger than the characteristic frequency of the two-level system. A derivation of the approximation is presented and the time evolution of the two-level-system occupation probability is calculated using both thermal- and coherent-state initial conditions for the oscillator. Closed-form evaluation of the time evolution in the weak-coupling limit provides insight into the differences between the thermal- and coherent-state models. Finally, potential experimental observations in solid-state systems, particularly the Cooper-pair box--nanomechanical resonator system, are discussed and found to be promising.

Recent experiments on quantum behavior in microfabricated solid-state systems suggest tantalizing connections to quantum optics. Several of these experiments address the prototypical problem of cavity quantum electrodynamics: a two-level system coupled to a quantum harmonic oscillator. Such devices may allow the exploration of parameter regimes outside the near-resonance and weak-coupling assumptions of the ubiquitous rotating-wave approximation (RWA), necessitating other theoretical approaches. One such approach is an adiabatic approximation in the limit that the oscillator frequency is much larger than the characteristic frequency of the two-level system. A derivation of the approximation is presented and the time evolution of the two-level-system occupation probability is calculated using both thermal- and coherent-state initial conditions for the oscillator. Closed-form evaluation of the time evolution in the weak-coupling limit provides insight into the differences between the thermal- and coherent-state models. Finally, potential experimental observations in solid-state systems, particularly the Cooper-pair box--nanomechanical resonator system, are discussed and found to be promising.

Archive-It Partner 652: University at Albany SUNY - Collection 10432: System Dynamics Society

[22 leaves]

We investigate the cosmological dynamics of non-minimally coupled scalar field system described by $F(\phi)R$ coupling with $F(\phi)=(1-\xi\phi^N)R$($N\ge2$) and the field potential, $V(\phi)=V_0\phi^n$. We use a generic set of dynamical variables to bring out new asymptotic regimes of the underlying dynamics. However, our dynamical variables miss the most important fixed point$-$ the de Sitter solution. We make use of the original form of system of equations to investigate the issues related to this important solution. In particular, we show that the de-Sitter solution which is a dynamical attractor of the system lies in the region of negative effective gravitational constant $G_N$ thereby leading to a ghost dominated universe in future and a transient quintessence(phantom) phase with $G_N>0 $ around the present epoch (however, as demonstrated by Starobinsky in 1981, the ghost dominated universe, if exists, can not be accessed from the Universe we live in, we shall say more about this important result in the last section). We also carry out comparison of the model with other competing models of dark energy such as galileon modified gravity and others.

We formulate an optimal load control (OLC) problem in power networks where the objective is to minimize the aggregate cost of tracking an operating point subject to power balance over the network. We prove that the swing dynamics and the branch power flows, coupled with frequency-based load control, serve as a distributed primal-dual algorithm to solve OLC. Even though the system has multiple equilibrium points, we prove that it nonetheless converges to an optimal point. This result implies that the local frequency deviations at each bus convey exactly the right information about the global power imbalance for the loads to make individual decisions that turn out to be globally optimal. It allows a completely decentralized solution without explicit communication among the buses. Simulations show that the proposed OLC mechanism can resynchronize bus frequencies with significantly improved transient performance.

The reduced dynamics of a central spin coupled to a bath of N spin-1/2 particles arranged in a spin star configuration is investigated. The exact time evolution of the reduced density operator is derived, and an analytical solution is obtained in the limit of an infinite number of bath spins, where the model shows complete relaxation and partial decoherence. It is demonstrated that the dynamics of the central spin cannot be treated within the Born-Markov approximation. The Nakajima-Zwanzig and the time-convolutionless projection operator technique are applied to the spin star system. The performance of the corresponding perturbation expansions of the non-Markovian equations of motion is examined through a comparison with the exact solution.

On example of the model field system we demonstrate that quantum fluctuations of non-abelian gauge fields leading to radiative corrections to Higgs potential and spontaneous symmetry breaking can generate order region in phase space of inherently chaotic classical field system. We demonstrate on the example of another model field system that quantum fluctuations do not influence on the chaotic dynamics of non-abelian Yang--Mills fields if the ratio of bare coupling constants of Yang--Mills and Higgs fields is larger then some critical value. This critical value is estimated.

A toy top is defined as a rotationally symmetric body moving in a constant gravitational field while one point on the symmetry axis is constrained to stay in a horizontal plane. It is an integrable system similar to the Lagrange top. Euler-Poisson equations are derived. Following Felix Klein, the special unitary group $\rm SU(2)$ is used as configuration space and the solution is given in terms of hyperelliptic integrals. The curve traced by the point moving in the horizontal plane is analyzed, and a qualitative classification is achieved. The cases in which the hyperelliptic integrals degenerate to elliptic ones are found and the corresponding solutions are given in terms of Weierstrass elliptic functions.

This paper investigates disentanglement as a result of evolution according to a class of master equations which include dissipation and interparticle interactions. Generalizing an earlier result of Di\'{o}si, the time taken for complete disentanglement is calculated (i.e. for disentanglement from any other system). The dynamics of two harmonically coupled oscillators is solved in order to study the competing effects of environmental noise and interparticle coupling on disentanglement. An argument based on separability conditions for gaussian states is used to arrive at a set of conditions on the couplings sufficient for all initial states to disentangle for good after a finite time.

This paper investigates disentanglement as a result of evolution according to a class of master equations which include dissipation and interparticle interactions. Generalizing an earlier result of Di\'{o}si, the time taken for complete disentanglement is calculated (i.e. for disentanglement from any other system). The dynamics of two harmonically coupled oscillators is solved in order to study the competing effects of environmental noise and interparticle coupling on disentanglement. An argument based on separability conditions for gaussian states is used to arrive at a set of conditions on the couplings sufficient for all initial states to disentangle for good after a finite time.

We apply an analysis of time-dependent spin-polarized current in a semiconductor channel at room temperature to establish how the magnetization configuration and dynamics of three ferromagnetic terminals, two of them biased and third connected to a capacitor, affect the currents and voltages. In a steady state, the voltage on the capacitor is related to spin accumulation in the channel. When the magnetization of one of the terminals is rotated, a transient current is triggered. This effect can be used for electrical detection of magnetization reversal dynamics of an electrode or for dynamical readout of the alignment of two magnetic contacts.

The dynamics of units (molecules) with slowly relaxing internal states is studied as an iterated function system (IFS) for the situation common in e.g. biological systems where these units are subjected to frequent collisional interactions. It is found that an increase in the collision frequency leads to successive discrete states that can be analyzed as partial steps to form a Cantor set. By considering the interactions among the units, a self-consistent IFS is derived, which leads to the formation and stabilization of multiple such discrete states. The relevance of the results to dynamical multiple states in biomolecules in crowded conditions is discussed.

We generalize Galam's model of opinion spreading by introducing three competing choices. At each update, the population is randomly divided in groups of three agents, whose members adopt the opinion of the local majority. In the case of a tie, the local group adopts opinion A, B or C with probabilities alpha, beta and (1-alpha-beta) respectively. We derive the associated phase diagrams and dynamics by both analytical means and simulations. Polarization is always reached within very short time scales. We point out situations in which an initially very small minority opinion can invade the whole system.

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