Values Of Physical Quantities Research Articles

Inference in quantum physics

In quantum physics all experimental information is discrete and stochastic. But the values of physical quantities are considered to depict definite properties of the physical world. Thus physical quantities should be identified with mathematical variables which are derived from the experimental data, but which exhibit as little randomness as possible. We look for such variables in two examples by investigating how it is possible to arrive at a value of a physical quantity from intrinsically stochastic data. With the aid of standard probability calculus and elementary information theory, we are necessarily led to the quantum theoretical phases and state vectors as the first candidates for physical quantities.

On quantum-mechanical automata

An automaton which can “measure” or “know” or “predict” the values of physical quantities cannot be described by quantum mechanics.

A new “parametrization” of the differential cross section for elastic scattering

A new parametrization of the differential cross section for elastic scattering is proposed. The parametrization incorporates correct analytic properties of the differential cross section and is based on optimized polynomial expansions of an analytic function. It is, in principle, valid for all energies and all angles. The parametrization has been tested for pp, p p , pd, π ± and K ±p elastic scattering at high energies and small angles. The results of the new fits are compared with those of the old ones. It has been found that with the same number of parameters one obtains practically the same values of χ 2. However, the new values of physical quantities, such as slope, α and (d σ/d t) 0, in most cases differ considerably from those obtained by the old parametrization. In particular, it has been found that the slope of the differential cross section for pp, p p , pd and K ±p elastic scattering increases continuously as the forward direction is approached.

Thermodynamics of monopolar continuum of grade $n$

Contrary to the theory of the simple material it is assumed that the values of physical quantities at a point are arrected by the deformation history of a finite neighborhood of the point. In the case of the monopolar continuum of grade $n$, the physical quantities are in a functional dependence on the temperature and, moreover, on 4n$ deformation gradients which are found from a single shift function. Equations of equilibrium and the boundary values for all $n$ stress tensors are evaluated on the basis of the First Law of Thermodynamics. Introducing the Hilbert space with the norm which expresses the fading of the memory it is possible to derive the system of constitutive equations from the Second Law of Thermodynamics. These equations enable us to evaluate the entropy as well as all stress tensors provided the functional dependence of the free energy on the history of $n$ deformation gradients and on the history of temperature is given.

The relation between the mean values of physical quantities and the S-matrix

The relation between the mean values of physical quantities and the S-matrix

Strong Quantum Damping of Helicons in Degenerate Semiconductors in Cylindrical Shape

Excitation of helicon modes is discussed for the plasma which is composed of degenerate electron gas and bounded by an infinitely long cylinder. Static magnetic field is given parallel to the axis of cylinder. Even for high magnetic field diagonal elements of the dielectric tensor can not be neglected in the dispersion relations unlike in the case for infinite medium. They give quantum effects in low temperature and the electric field shows strong damping and oscillatory behavior with magnetic field. Numerical calculations are carried out with appropriate values of physical quantities, InSb being chosen as a most favorable example.