arXiv subjects

J. C. Flores

Publications and source records attributed to J. C. Flores.

At least 19 recordsLinked to original sources

arXiv2010

Mathematical Model of Easter Island Society Collapse

In this paper we consider a mathematical model for the evolution and collapse of the Easter Island society, starting from the fifth century until the last period of the society collapse (fifteen century). Based on historical reports, the available primary sources consisted almost exclusively on the trees. We describe the inhabitants and the resources as an isolated system and both considered as dynamic variables. A mathematical analysis about why the structure of the Easter Island community collapse is performed. In particular, we analyze the critical values of the fundamental parameters driving the interaction humans-environment and consequently leading to the collapse. The technological parameter, quantifying the exploitation of the resources, is calculated and applied to the case of other extinguished civilization (Copán Maya) confirming, with a sufficiently precise estimation, the consistency of the adopted model.

q-bio.PE↗

arXiv2009

Quantum capacitor with discrete charge-anticharge: spectrum and forces

The quantum capacitor with discrete charge is modeled by a Hamiltonian containing an inductive intrinsic term (tunnel effect between plates). The spectrum is obtained using a double Hilbert space. Fluctuations in the charge-anticharge pairs (zero total charge) give rise to an elementary attraction which is compared to the Casimir force. In this case, the field-fluctuations force could be also interpreted as charge-fluctuations force.

cond-mat.mes-hall↗

arXiv2008

Anderson localization and the Planck length as source of disorder

The role of disorder on wave propagation through the universe is studied. Assuming space fluctuations of the order of the Planck length and the size of the universe as the corresponding localization length for the background radiation, we obtain the exponent (close to unity) in the power law relationship between these quantities. This suggests that the role of Anderson localization is not negligible at cosmological scales.

cond-mat.dis-nn↗

arXiv2008

Is planetary chaos related to evolutionary (phenotypic) rates?

After Laskar, the Lyapunov time in the solar system is about five millions years (5.000.000 [years]). On the other hand, after Kimura, the evolutionary (phenotypic) rate, for hominids, is 1/5.000.000 [1/years]. Why are these two quantities so closely related? In this work, following a proposition by Finlayson and Hutchings et al, I found an inequality, which relates Lyapunov time and evolution rate. This inequality fits well with some known cases in biological evolution.

q-bio.PE↗

arXiv2006

An axiomatic theory for interaction between species in ecology: Gause's exclusion conjecture

I introduce an axiomatic representation, called ecoset, to consider interactions between species in ecological systems. For interspecific competition, the exclusion conjecture (Gause) is put in a symbolic way and used as a basic operational tool to consider more complex cases like two species with two superposed resources (niche differentiation) and apparent competitors. Competition between tortoises and invaders in Galapagos islands is considered as a specific example. Our theory gives us an operative language to consider elementary process in ecology and open a route to more complex systems.

q-bio.PE↗

arXiv2006

Discrete-charge quantum circuits in semiclassical approach

We discuss a new approach to describe mesoscopic systems, based on the ideas of quantum electrical circuits with charge discreteness. This approach has allowed us to propose a simple alternative descriptions of some mesoscopic systems, with interesting results for some mesoscopic systems. In his work, we show that the application of the Bohr-Sommerfeld quantization rules to the Quantum $LC$ circuit with discrete charge allows us to easily reproduce previous results.

cond-mat.mes-hall↗

arXiv2006

Wavefront solution in extended quantum circuits with charge discreteness

A wavefront solution for quantum (capacitively coupled) transmission lines with charge discreteness (PRB {\bf 64}, 235309 (2001)) is proposed for the first time. The nonlinearity of the system becomes deeply related to charge discreteness. The wavefront velocity is found to depend on a step discontinuity on the (pseudo) flux variable, $f$, displaying allowed and forbidden regions (gaps), as a function of $f$. A preliminary study of the stability of the solutions is presented. The dual transmission line hamiltonian is proposed and finally, we find a connection with the (quantum) Toda lattice.

cond-mat.mes-hall↗

arXiv2005

Density of states of disordered systems with a finite correlation length

We consider a semiclassical formulation for the density of states (DOS) of disordered systems in any dimension. We show that this formulation becomes very accurate when the correlation length of the disorder potential is large. The disorder potential does not need to be smooth and is not limited to the perturbative regime, where the disorder is small. The DOS is expressed in terms of a convolution of the disorder distribution function and the non-disordered DOS. We apply this formalism to evaluate the broadening of Landau levels and to calculate the specific heat in disordered systems.

cond-mat.dis-nn↗

arXiv2005

Quantum LC circuits with charge discreteness: normal and anomalous spectrum

A solvable quantum $LC$ circuit with charge discreteness is studied. Two discrete spectral branches are obtained: (i) the normal branch corresponding to a charged capacitor with integer effective charge $k=q_{e}n$ ($q_{e}$ elementary charge, $n$ integer) and (ii) the anomalous branch where the energy is related to non-integer effective charge $k=q_{e}(n-x)$ in the capacitor. For usual mesoscopics data like quantum point contact we found $x\sim 0.7$.

cond-mat.mes-hall↗

arXiv2005

Symbology from set theory applied to ecological systems: Gause's exclusion principle and applications

We introduce a symbolic representation like set theory to consider ecologic interactions between species (ECOSET). The ecologic exclusion principle (Gause) is put in a symbolic way and used as operational tool to consider more complex cases like interaction with sterile species (SIT technique), two species with two superposed sources (niche differentiation) and N+P species competing by N resources, etc. Displacement (regional or characters) is also considered by using this basic tool. Our symbolic notation gives us an operative and easy way to consider elementary process in ecology. Some experimental data (laboratory or field) for ecologic process are re-considered under the optic of this set-theory.

q-bio.PE↗

arXiv2005

Anderson's localization in a random metric: applications to cosmology

It is considered an equation for the Lyapunov exponent $% γ$ in a random metric for a scalar propagating wave field. At first order in frequency this equation is solved explicitly. The localization length $L_{c}$ (reciprocal of Re($γ$)) is obtained as function of the metric-fluctuation-distance $ΔR$ (function of disorder) and the frequency $ω$ of the wave. Explicitly, low-frequencies propagate longer than high, that is $L_{c}ω^{2}=C^{te}$. Direct applications with cosmological quantities like background radiation microwave ($λ\sim 1/2\times 10^{-3}$ [m]) and the Universe-length (`localization length' $L_{c}\sim 1.6\times 10^{25}$ [m]) permits to evaluate the metric-fluctuations-distance as $ΔR\sim 10^{-35}$ [m], a number at order of the Planck's length.

gr-qc↗

arXiv2004

Simple approach to the mesoscopic open electron resonator: Quantum current oscillations

The open electron resonator, described by Duncan et.al, is a mesoscopic device that has attracted considerable attention due to its remarkable behaviour (conductance oscillations), which has been explained by detailed theories based on the behaviour of electrons at the top of the Fermi sea. In this work, we study the resonator using the simple quantum quantum electrical circuit approach, developed recently by Li and Chen. With this approach, and considering a very simple capacitor-like model of the system, we are able to theoretically reproduce the observed conductance oscillations. A very remarkable feature of the simple theory developed here is the fact that the predictions depend mostly on very general facts, namely, the discrete nature of electric charge and quantum mechanics; other detailed features of the systems described enter as parameters of the system, such as capacities and inductances.

cond-mat.mes-hall↗

arXiv2003

Spectral and thermodynamical properties of systems with noncanonical commutation rules: semiclassical approach

We study different quantum one dimensional systems with noncanonical commutation rule $[x,p]=i\hbar (1+sH),$ where $H$ is the one particle Hamiltonian and $s$ is a parameter. This is carried-out using semiclassical arguments and the surmise $\hbar \to \hbar (1+sE),$ where $E$ is the energy. We compute the spectrum of the potential box, the harmonic oscillator, and a more general power-law potential $| x| ^ν$% . With the above surmise, and changing the size of the elementary cell in the phase space, we obtain an expression for the partition function of these systems. We calculate the first order correction in $s$ for the internal energy and heat capacity. We apply our technique to the ideal gas, the phonon gas, and to $N$ non-interacting particles with external potential like $| x| ^ν$.

quant-ph↗

arXiv2001

Mesoscopic circuits with charge discreteness:quantum transmission lines

We propose a quantum Hamiltonian for a transmission line with charge discreteness. The periodic line is composed of an inductance and a capacitance per cell. In every cell the charge operator satisfies a nonlinear equation of motion because of the discreteness of the charge. In the basis of one-energy per site, the spectrum can be calculated explicitly. We consider briefly the incorporation of electrical resistance in the line.

cond-mat.mes-hall↗

arXiv2000

Gause's exclusion principle revisited: artificial modified species and competition

Gause's principle of competition between two species is studied when one of them is sterile. We study the condition for total extinction in the niche, namely, when the sterile population exterminates the native one by an optimal use of resources. A mathematical Lotka-Volterra non linear model of interaction between a native and sterile species is proposed. The condition for total extinction is related to the initial number $M_{o}$ of sterile individuals released in the niche. In fact, the existence of a critical sterile-population value $M_{c}$ is conjectured from numerical analysis and an analytical estimation is found. When spatial diffusion (migration) is considered a critical size territory is found and, for small territory, total extinction exist in any case. This work is motived by the extermination agriculture problem of fruit flies in our region.

nlin.AO↗

arXiv2000

Chapman's model for ozone concentration: earth`s slowing rotation effect in the atmospheric past

Chapman's model for ozone concentration is studied. In this nonlinear model, the photodissociation coefficients for $O_{2}$ and $O_{3}$ are time-depending due to earth-rotation. From the Kapitsa's method, valid in the high frequency limit, we find the criterion for the existence of equilibrium solutions. These solutions are depending on the frequency, and require a rotation period $T$ which satisfies $T T_{2}$. Where the critical periods $T_{1}$ and $T_{2}$, with $T_{2}>T_{1}$, are a function of the parameters of the system (reaction rates and photodissociation coefficients). Conjectures respect to the retardation of the earth's rotation, due to friction, suggest that the criterion was not even verified in the atmospheric past.

physics.ao-ph↗

arXiv2000

Delocalization of two interacting particles in a random potential: One-dimensional electric interaction

We consider a continuous one dimensional model of two charged interacting particles in a random potential. The electric repulsion is strictly one dimensional and it inhibits Anderson localization. In fact, the spectrum is continuous. The case of electrical atraction is briefly studied and it shows bounded states. So, the dynamics is sign dependent for this model. We support our analytical results with numerical simulations where the effect of repulsion breaking localization is clearly observed.

cond-mat.dis-nn↗

arXiv2000

Phase-coherence time saturation in mesoscopic systems: wave function collapse

A finite phase-coherence time $τ_ϕ^{meas}$ emerges from iterative measurement onto a quantum system. For a rapid sequence, the phase-coherence time is found explicitly. For the stationary charge conduction problem, it is bounded. At all order, in the time-interval of measurements, we propose a general expression for $τ_ϕ^{meas}$.

cond-mat.mes-hall↗