Search results for "Number operator"
showing 10 items of 10 documents
Non-hermitian operator modelling of basic cancer cell dynamics
2018
We propose a dynamical system of tumor cells proliferation based on operatorial methods. The approach we propose is quantum-like: we use ladder and number operators to describe healthy and tumor cells birth and death, and the evolution is ruled by a non-hermitian Hamiltonian which includes, in a non reversible way, the basic biological mechanisms we consider for the system. We show that this approach is rather efficient in describing some processes of the cells. We further add some medical treatment, described by adding a suitable term in the Hamiltonian, which controls and limits the growth of tumor cells, and we propose an optimal approach to stop, and reverse, this growth.
A PHENOMENOLOGICAL OPERATOR DESCRIPTION OF INTERACTIONS BETWEEN POPULATIONS WITH APPLICATIONS TO MIGRATION
2013
We adopt an operatorial method based on the so-called creation, annihilation and number operators in the description of different systems in which two populations interact and move in a two-dimensional region. In particular, we discuss diffusion processes modeled by a quadratic hamiltonian. This general procedure will be adopted, in particular, in the description of migration phenomena. With respect to our previous analogous results, we use here fermionic operators since they automatically implement an upper bound for the population densities.
Traces of symmetry-adapted reduced density operators
1990
Formulae are derived for traces of symmetry-adapted reduced density operators in a finite-dimensional, antisymmetric and spin-adapted space. The traces are expressed in terms of traces of products of the orbital occupation number operators.
Simplified stock markets and their quantum-like dynamics
2009
In this paper we continue our systematic analysis of the operatorial approach previously proposed in an economical context and we discuss a mixed toy model of a simplified stock market, i.e. a model in which the price of the shares is given as an input. We deduce the time evolution of the portfolio of the various traders of the market, as well as of other observable quantities. As in a previous paper, we solve the equations of motion by means of a fixed point like approximation.
A quantum statistical approach to simplified stock markets
2009
We use standard perturbation techniques originally formulated in quantum (statistical) mechanics in the analysis of a toy model of a stock market which is given in terms of bosonic operators. In particular we discuss the probability of transition from a given value of the {\em portfolio} of a certain trader to a different one. This computation can also be carried out using some kind of {\em Feynman graphs} adapted to the present context.
A model of adaptive decision-making from representation of information environment by quantum fields
2017
We present the mathematical model of decision making (DM) of agents acting in a complex and uncertain environment (combining huge variety of economical, financial, behavioral, and geo-political factors). To describe interaction of agents with it, we apply the formalism of quantum field theory (QTF). Quantum fields are of the purely informational nature. The QFT-model can be treated as a far relative of the expected utility theory, where the role of utility is played by adaptivity to an environment (bath). However, this sort of utility-adaptivity cannot be represented simply as a numerical function. The operator representation in Hilbert space is used and adaptivity is described as in quantu…
Toward a formalization of a two traders market with information exchange
2014
This paper shows that Hamiltonians and operators can also be put to good use even in contexts which are not purely physics based. Consider the world of finance. The work presented here {models a two traders system with information exchange with the help of four fundamental operators: cash and share operators; a portfolio operator and an operator reflecting the loss of information. An information Hamiltonian is considered and an additional Hamiltonian is presented which reflects the dynamics of selling/buying shares between traders. An important result of the paper is that when the information Hamiltonian is zero, portfolio operators commute with the Hamiltonian and this suggests that the dy…
Stress in emergency telephone number operators during the COVID-19 pandemic: the role of self-efficacy and Big Five personality traits
2022
BackgroundEmergency telephone number operators experience many challenges in their work during the COVID-19 pandemic. Their personality traits and self-efficacy may act as important factors in their level of perceived stress. The aim of this study was to determine the relationship between Big Five personality traits, self-efficacy and perceived stress among emergency tele-phone number operators during the COVID-19 pandemic.Participants and procedureOne hundred emergency telephone number operators participated in the study. The Perceived Stress Scale (PSS-10), Ten Item Personality Inventory (TIPI) and Generalized Self Efficacy Scale (GSES) were used.ResultsEmergency telephone number operator…
A Phenomenological Operator Description of Dynamics of Crowds: Escape Strategies
2015
Abstract We adopt an operatorial method, based on creation, annihilation and number operators, to describe one or two populations mutually interacting and moving in a two-dimensional region. In particular, we discuss how the two populations, contained in a certain two-dimensional region with a non-trivial topology, react when some alarm occurs. We consider the cases of both low and high densities of the populations, and discuss what is changing as the strength of the interaction increases. We also analyze what happens when the region has either a single exit or two ways out.