On the concept of time and the origin of the cosmological temperature

Time arises in the theory of gravity through the semiclassical approximation of the gravitational part of the solution of the Wheeler-De Witt equation in the manner shown by Banks (SCAG). We generalize Banks' procedure by grafting a Born-Oppenheimer type approximation onto SCAG. This allows for the feedback of matter onto gravity, wherein the latter is driven by the (quantum) mean energy-momentum tensor of matter. The wave function is nonvanishing in classically forbidden configurations of gravity. In SCAG this is described by the evolution of matter in imaginary time. This is interpreted as an inverse temperature, and the norm of the matter wave function, no longer conserved for these gravitational configurations, is a partition function. A simple cosmological model is worked out to illustrate these ideas. In this model it is shown that the temperature of the matter which emerges into the classically permitted region is the inverse bounce time of the bounce executed by the system in the forbidden region (behind the horizon).Time present and time past are both perhaps present in time future. And time future contained in time past. If all time is eternally present All time is unredeemable.—T. S. Eliot, Burnt Norton,Four Quartets, 1943.In honor of Ilya Prigogine on the occasion of his 70th birthday.     

Multifractal analysis of the Korean agricultural market

We have studied the long-term memory effects of the Korean agricultural market using the detrended fluctuation analysis (DFA) method. In general, the return time series of various financial data, including stock indices, foreign exchange rates, and commodity prices, are uncorrelated in time, while the volatility time series are strongly correlated. However, we found that the return time series of Korean agricultural commodity prices are anti-correlated in time, while the volatility time series are correlated. The $n$-point correlations of time series were also examined, and it was found that a multifractal structure exists in Korean agricultural market prices.     

Some consequences of the superposition of anomalous charging and discharging currents in dielectrics

An analysis of the time dependence of the anomalous discharging current, which flows through a dielectric after it has been charged for a finite period of time, is carried out. The validity of thet ^–n law for the anomalous charging current is assumed in the time interval under consideration, i.e. in times shorter than the mean relaxation time. It is shown that the shape of the log (anomalous discharging current) — log (time) curve for a charging periodt _c in this case is similar to that of the log (anomalous discharging current) — log (time) curve obtained after the infinite charging, if the mean relaxation time is neart _c . This fact may lead to a false interpretation of the experimental results. Corrections for the determination of the true magnitude and slope of the time dependent anomalous discharging current are given in the case of finite charging periods of time.     

Chaotic motion at the emergence of the time averaged energy decay

A system plus environment conservative model is used to characterize the nonlinear dynamics when the time averaged energy for the system particle starts to decay. The system particle dynamics is regular for low values of the N environment oscillators and becomes chaotic in the interval 13≤N≤15, where the system time averaged energy starts to decay. To characterize the nonlinear motion we estimate the Lyapunov exponent (LE), determine the power spectrum and the Kaplan-Yorke dimension. For much larger values of N the energy of the system particle is completely transferred to the environment and the corresponding LEs decrease. Numerical evidence shows the connection between the variations of the amplitude of the particles energy time oscillation with the time averaged energy decay and trapped trajectories.     

Generalization of the Fresnel law to the case of a pressure-wave-induced displacement of the interface between acoustic media

The problem of interaction between a nonsteady-state pressure wave and a moving interface between acoustic media is analyzed and solved for the first time with allowance for a finite displacement of the interface induced by the wave. An analytic solution is obtained using a nonlinear time transformation method. Expressions are obtained for the law of motion of the interface, and for the reflected and transmitted waves as a function of the time profile of the incident wave and the acoustic characteristics of the media. Zh. Tekh. Fiz. 69, 114–115 (April 1999)     

Hierarchy of Times for the Establishment of the Gibbs Distribution

Doklady Physics - It is shown that there are three characteristic time scales for the establishment of thermodynamic equilibrium: the time for the thermalization of the system; the time for...     

Forecasting the underlying potential governing the time series of a dynamical system

We introduce a technique of time series analysis, potential forecasting, which is based on dynamical propagation of the probability density of time series. We employ polynomial coefficients of the orthogonal approximation of the empirical probability distribution and extrapolate them in order to forecast the future probability distribution of data. The method is tested on artificial data, used for hindcasting observed climate data, and then applied to forecast Arctic sea-ice time series. The proposed methodology completes a framework for ‘potential analysis’ of tipping points which altogether serves anticipating, detecting and forecasting nonlinear changes including bifurcations using several independent techniques of time series analysis. Although being applied to climatological series in the present paper, the method is very general and can be used to forecast dynamics in time series of any origin.     

Coherent and incoherent exciton motion in the framework of the continuous time random walk

We derive the hopping time distribution functions of the continuous time random walk theory starting from an exact kernel for one-dimensional exciton motion. The derivation is based on exact relations between the kernel and the hopping time distribution functions.     

Statistics of the Occupation Time of Renewal Processes

We present a systematic study of the statistics of the occupation time and related random variables for stochastic processes with independent intervals of time. According to the nature of the distribution of time intervals, the probability density functions of these random variables have very different scalings in time. We analyze successively the cases where this distribution is narrow, where it is broad with index <1, and finally where it is broad with index 1<<2. The methods introduced in this work provide a basis for the investigation of the statistics of the occupation time of more complex stochastic processes (see joint paper by G. De Smedt, C. Godrèche, and J. M. Luck⁽²⁶⁾).     

Correlation functions of the Ising model of solid ortho-hydrogen in the disordered phase

In a generalized molecular field approximation the time independent correlation functions as well as the time dependent ones are calculated for the Ising model of o-H₂ in the orientationally disordered phase. In our treatment the correlations fulfill their characteristic sum rule automatically. The order parameter correlation shows the characteristic singularity at the stability limit fork=0. The time dependent correlations are calculated within the Glauber stochastic model and show critical behaviour at the stability limit.     

Time Evolution of the two-jet eventse +−e −→Hadrons in the Dynamical String Model

The time dependent pion emission rate and the mean life time of the pion source in the center of mass frame of the two-jet events have been determined fore ⁺?e ^?→hadrons at √s=20 – 50 GeV by the Dynamical String Model. It was established that the time needed for the creation of the pion source is 5 fm/c, whereas its life time is τ₀=7 – 13 fm/c for energies √s=20 – 50 GeV, respectively.     

A probabilistic analysis of the difficulties of unifying quantum mechanics with the theory of relativity

A procedure is given for the transformation of quantum mechanical operator equations into stochastic equations. The stochastic equations reveal a simple correlation between quantum mechanics and classical mechanics: Quantum mechanics operates with “optimal estimations,” classical mechanics is the limit of “complete information.” In this connection, Schrödinger's substitution relationsp _x → -i? ?/?x, etc, reveal themselves as exact mathematical transformation formulas. The stochastic version of quantum mechanical equations provides an explanation for the difficulties in correlating quantum mechanics and the theory of relativity: In physics “time” is always thought of as a numerical parameter; but in the present formalism of physics “time” is described by two formally totally different quantities. One of these two “times” is a numerical parameter and the other a random variable. This last concept of time shows all the properties required by the theory of relativity and is therefore to be considered as the relativistic time.     

Effect of time delay on the upper bound of the time derivative of information entropy in a stochastic dynamical system

The effects of the time delay on the upper bound of the time derivative of information entropy are investigated in a time-delayed dynamical system driven by correlated noise. Using the Markov approximation of the stochastic delay differential equations and the Schwartz inequality principle, we obtain an analytical expression for the upper bound U_B(t) of the time derivative of the information entropy. The results show that there is a critical value of τ (delay time), and U_B(t) presents opposite behaviours on difference sides of the critical value. For the case of the weak additive noise, τ can induce a reentrance transition. Delay time τ also causes a reversal behaviour in U_B(t)-λ plot, where λ denotes the degree of the correlation between the two noises.     

On the Dynamics of Kac p-Spin Glasses

This paper discusses the dynamical properties of p-spin models with Kac interactions. For large but finite interaction range R one finds two different well separated time scales for relaxation. A first short time scale, roughly independent of R, on which the system remains confined to limited regions of the configuration space and an R dependent long time scale on which the system is able to escape from the confining regions. I will argue that the R independent time scales can be described through dynamical mean field theory, while non-perturbative new techniques have to be used to deal with the R dependent scales.     

色噪声间关联的周期调制对单模激光随机共振的影响

讨论色噪声驱动的单模激光系统在噪声间关联程度受时间周期调制情况下的随机共振.用线性化近似的方法计算了光强功率谱及信噪比.具体讨论色噪声情况下信噪比R受噪声强度D,Q,时间周期调制频率Ω_λ以及噪声自关联时间τ₁,τ₂和噪声间关联程度λ的影响.发现信噪比随噪声强度的变化呈单峰共振,信噪比随时间周期调制频率的变化呈周期性共振,而信噪比随 关键词： 色噪声 时间周期调制 噪声间关联程度 周期性随机共振     

Experimental study of the relationships between the spectral emissivity of brass and the temperature in the oxidizing environment

Effect of surface oxidization on the spectral emissivity of brass is studied over the temperature range from 800 to 1070 K at the wavelength of 1.5 μm. The temperature of brass surface is measured by averaging the two R-type platinum–rhodium thermocouples. The radiant energy emitted by the brass surface is received by an InGaAs photodiode detector. Two kinds of relationships between the spectral emissivity and the temperature are investigated in the oxidizing environment at the elevated temperature. One is the variation of spectral emissivity with the heating-duration time at the given temperature. The other is the variation of spectral emissivity with the temperature at the given heating-duration time. The interference effect of radiation coming from the brass surface and coming from the oxidization film is discussed when the oxidation film on the surface is grown. The resonant structures of spectral emissivity are observed during the whole heating period, in particular at the early stage of heating duration. The analytic formula of spectral emissivity versus the temperature is derived at the heating-duration time of 30, 60, 90, 120, 150, 180, 210, 240, 270 and 300 min, respectively. The conclusion is obtained that coefficients of analytic expressions between the spectral emissivity and the temperature are different from each other for the experimental results obtained at the different heating-duration time, though the polynomial functional form is suitable to fit all the measurements obtained in the present work.     

High temperature superconductivity in the mixed state and the dynamics of charge carriers

A model to calculate the temperature and magnetic field dependence of the scattering time τ_ν(H, T) of quasiparticles by bound electron states in a vortex in high-temperature superconductors is proposed. In this model, the hydrodynamic interaction of a moving gas of quasiparticles with the discrete states of the vortex velocity field is regarded as quasielastic scattering and the resulting scattering time of quasiparticles is different from scattering of individual vortices. The normalized scattering time was found to decrease exponentially with increasing temperature. This behavior is due to the suppression of the amplitude of the superconducting order parameter as the temperature increases. This model accounts for the observed temperature and field dependence of the scattering time particularly at low-field regime.     

Effect of annealing time on the structural and ferromagnetic properties of the GaMnN thin films

GaMnN thin films were deposited on a sapphire (0001) substrate by using laser assisted molecular beam epitaxy. Subsequently, the samples were annealed in the ammonia ambience at 1000 °C for different time lengths. The crystalline quality was improved gradually, and the room temperature ferromagnetism of our samples becomes stronger with the increase of the annealing time within 25 min. The X-ray photoelectron spectra analysis confirmed that the Mn³⁺ concentration in the GaMnN films increased after annealing. The stronger ferromagnetism was observed in the sample with the higher Mn³⁺ concentration. However, too long annealing time, such as 35 min, will lead to the degradation of the crystalline quality and the decrease of Mn³⁺ concentration, which results in the weakened ferromagnetism. The optimal annealing time is 25 min at 1000 °C in our experiments. Finally, the origin of the room temperature ferromagnetism in our samples was discussed preliminarily.     

Calibration of scintillation counters of the upgraded calorimeter of the IHEP-JINR Neutrino Detector for time of flight particle identification

In this paper, specific features of operation of the calorimeter of the IHEP-JINR Neutrino Detector on the basis of liquid scintillation counters upgraded for time of flight particle identification are described. Data acquisition system, algorithms of response reconstruction, and calibration of calorimeter counters are described in detail. Estimate of time and spatial resolution of counters is obtained on tracks of vertical cosmic muons. The averaged time resolution is σ = 1.2 ns, and the coordinate resolution is σ = 13 cm.