Search results for "Philosophy of mathematics"
showing 10 items of 246 documents
Multimode time-dependent gyrotron equations for different time scales
2017
The work of H.K. was supported by the European Regional Development Funding of the Project No. 1.1.1.1/ 16/A/004.
Nitrogen broadening of SF6 transitions in the nu3 band
2001
Abstract Nitrogen induced pressure-broadened halfwidths of a number of ν3 transitions of SF6 are calculated using the complex Robert–Bonamy (CRB) formalism. The calculations are made at 200, 250, 296 and 350 K and the temperature dependence of the halfwidths are determined. The intermolecular potential is taken as a sum of the leading electrostatic and Lennard-Jones [6] , [7] , [8] , [9] , [10] , [11] , [12] atom–atom components. The dynamics of the collision process are correct to second order in time. The calculated halfwidths are used to simulate the ν3 spectrum, which is compared to a simulation made using the HITRAN96 halfwidths and measurements made at the Universite Pierre et Marie C…
Evolutionary distances corrected for purifying selection and ancestral polymorphisms.
2019
Abstract Evolutionary distance formulas that take into account effects due to ancestral polymorphisms and purifying selection are obtained on the basis of the full solution of Jukes–Cantor and Kimura DNA substitution models. In the case of purifying selection two different methods are developed. It is shown that avoiding the dimensional reduction implicitly carried out in the conventional model solving is instrumental to incorporate the quoted effects into the formalism. The problem of estimating the numerical values of the model parameters, as well as those of the correction terms, is not addressed.
A Note on Laws of Motion for Aggregate Distributions
2020
I derive the law of motion for the aggregate distribution directly from the laws of motion for the individuals’ states. By relying on concepts from measure theory, the derivation is concise and intuitive. I address random shocks both at the micro level and at the macro level. Micro-level shocks completely cancel at the aggregate level provided that a law of large numbers applies. Therefore, the law of motion for the aggregate distribution is a deterministic process in the absence of macro-level uncertainty. If there are macro-level risks, the law of motion for the aggregate distribution exhibits a stochastic component additionally. I illustrate the formalism in a model of wealth accumulatio…
Activity coefficients and Donnan coion exclusion in charged membranes with weak-acid fixed charge groups
1998
Abstract We have studied theoretically the effects that the dissociation equilibrium of weak-acid fixed charge groups (e.g. carboxyl groups) exerts on the mean activity coefficients in charged membranes using a Donnan formalism. The model calculations indicate that unless carbon dioxide is excluded from the external aqueous solution, the pH of the membrane solution can be low enough to affect significantly the effective fixed charge concentration and the coion exclusion when the membrane fixed charge concentration is high compared with the external solution salt concentration. Although this problem was already pointed out in previous studies, the possibility that the pH and salt concentrati…
Adiabatic evolution of quantum-mechanical systems
1991
A description of the adiabatic approximation in terms of the time-evolution operator is presented. Corrections to the approximation are studied, and it is seen that these can be obtained in a simple way in the case of a rapidly oscillating Hamiltonian.
Functional Derivative Approach
2001
Let us now leave the path integral formalism temporarily and reformulate operatorial quantum mechanics in a way which will make it easy later on to establish the formal connection between operator and path integral formalism. Our objective is to introduce the generating functional into quantum mechanics. Naturally we want to generate transition amplitudes. The problem confronting us is how to transcribe operator quantum mechanics as expressed in Heisenberg’s equation of motion into a theory formulated solely in terms of c-numbers. This can be achieved either by Schwinger’s action principle or with the aid of a generation functional defined as follows:
Application of molecular topology to the prediction of antifungal activity for a set of dication-substituted carbazoles, furans and benzimidazoles
2003
In this paper, the endpoint is the application of molecular topology to the search of QSAR relations into a group of dicationsubstituted carbazoles, furans and benzimidazoles, all showing antifungal activity against C. albicans. Mathematical and statistical methods such as linear regression and discriminant analysis, are used to goal. The obtained results clearly show a high efficiency of the formalism on the prediction and classification of antifungal activity. 83% of the compounds showing MIC , 10 mg/ml (active group) are correctly classified, whilst 100% overall accuracy is achieved for those compounds showing MIC . 100 mg/ml (inactive group). q 2003 Elsevier Science B.V. All rights rese…
Dynamically generated N* resonances from the interaction of two mesons and a baryon
2009
We have studied the ππN system and coupled channels by using of the Faddeev equations and two N* and one Δ states, all of them with JP = 1/2+, have been found in the formalism as dynamically generated states. In addition, signatures for a new N* resonance with JP = 1/2+ are found around an energy of 1920 MeV in the three-body center of mass system.
Black Holes in Extended Gravity Theories in Palatini Formalism
2013
We consider several physical scenarios where black holes within classical gravity theories including R 2 and Ricci-squared corrections and formulated a la Palatini can be analytically studied.