649 research outputs found
The ontology of Bohmian mechanics
The paper points out that the modern formulation of Bohm's quantum theory
known as Bohmian mechanics is committed only to particles' positions and a law
of motion. We explain how this view can avoid the open questions that the
traditional view faces according to which Bohm's theory is committed to a
wave-function that is a physical entity over and above the particles, although
it is defined on configuration space instead of three-dimensional space. We
then enquire into the status of the law of motion, elaborating on how the main
philosophical options to ground a law of motion, namely Humeanism and
dispositionalism, can be applied to Bohmian mechanics. In conclusion, we sketch
out how these options apply to primitive ontology approaches to quantum
mechanics in general
The physics and metaphysics of primitive stuff
The paper sets out a primitive ontology of the natural world in terms of
primitive stuff, that is, stuff that has as such no physical properties at all,
but that is not a bare substratum either, being individuated by metrical
relations. We focus on quantum physics and employ identity-based Bohmian
mechanics to illustrate this view, but point out that it applies all over
physics. Properties then enter into the picture exclusively through the role
that they play for the dynamics of the primitive stuff. We show that such
properties can be local (classical mechanics), as well as holistic (quantum
mechanics), and discuss two metaphysical options to conceive them, namely
Humeanism and modal realism in the guise of dispositionalism
Radiative magneto-hydrodynamics in massive star formation and accretion disks
We briefly overview our newly developed radiation transport module for MHD
simulations and two actual applications. The method combines the advantage of
the speed of the Flux-Limited Diffusion approximation and the high accuracy
obtained in ray-tracing methods.Comment: 2 pages, 1 figure, Proceedings of the IAU Symposium 259, Cosmic
Magnetic Fields: From Planets, to Stars and Galaxie
The Wave-Function Is a Multi-Field
It is generally argued that if the wave-function in the de Broglie--Bohm theory is a physical field, it must be a field in configuration space. Nevertheless, it is possible to interpret the wave-function as a multi-field in three-dimensional space. This approach hasn't received the attention yet it really deserves. The aim of this paper is threefold: first, we show that the wave-function is naturally and straightforwardly construed as a multi-field; second, we show why this interpretation is superior to other field interpretations; third, we clarify common misconceptions
The Wave-Function Is a Multi-Field
It is generally argued that if the wave-function in the de Broglie--Bohm theory is a physical field, it must be a field in configuration space. Nevertheless, it is possible to interpret the wave-function as a multi-field in three-dimensional space. This approach hasn't received the attention yet it really deserves. The aim of this paper is threefold: first, we show that the wave-function is naturally and straightforwardly construed as a multi-field; second, we show why this interpretation is superior to other field interpretations; third, we clarify common misconceptions
When Fields Are Not Degrees of Freedom
We show that in the Maxwell–Lorentz theory of classical electrodynamics most initial values for fields and particles lead to an ill-defined dynamics, as they exhibit singularities or discontinuities along light-cones. This phenomenon suggests that the Maxwell equations and the Lorentz force law ought rather to be read as a system of delay differential equations, that is, differential equations that relate a function and its derivatives at different times. This mathematical reformulation, however, leads to physical and philosophical consequences for the ontological status of the electromagnetic field. In particular, fields cannot be taken as independent degrees of freedom, which suggests that one should not add them to the ontology
When Fields Are Not Degrees of Freedom
We show that in the Maxwell–Lorentz theory of classical electrodynamics most initial values for fields and particles lead to an ill-defined dynamics, as they exhibit singularities or discontinuities along light-cones. This phenomenon suggests that the Maxwell equations and the Lorentz force law ought rather to be read as a system of delay differential equations, that is, differential equations that relate a function and its derivatives at different times. This mathematical reformulation, however, leads to physical and philosophical consequences for the ontological status of the electromagnetic field. In particular, fields cannot be taken as independent degrees of freedom, which suggests that one should not add them to the ontology
The Wave-Function Is a Multi-Field
It is generally argued that if the wave-function in the de Broglie--Bohm theory is a physical field, it must be a field in configuration space. Nevertheless, it is possible to interpret the wave-function as a multi-field in three-dimensional space. This approach hasn't received the attention yet it really deserves. The aim of this paper is threefold: first, we show that the wave-function is naturally and straightforwardly construed as a multi-field; second, we show why this interpretation is superior to other field interpretations; third, we clarify common misconceptions
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