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M. E. Pietrzyk

Publications and source records attributed to M. E. Pietrzyk.

3 recordsLinked to original sources

Modifications of Newtonian dynamics from higher moments of quantum spin connection in precanonical quantum gravity

Building upon previous work that derived an alternative to (galactic) dark matter in the form of Modified Newtonian Dynamics (MOND), with a specific theoretical interpolating function, from the motion of a non-relativistic test particle in the gravitational field of a point mass immersed in the non-relativistic static limit of the spin connection foam -- which represents the quantum analogue of Minkowski spacetime within precanonical quantum gravity -- we now show the consequences of using higher moments (third and fourth) of the corresponding geodesic equation with a random spin connection term. These higher moments lead to more general quantum modifications of the Newtonian potential (qMOND potentials expressed in terms of Gauss and Appell hypergeometric functions), more general (steeper) MOND interpolating functions, and a new modification of MOND at low accelerations (mMOND) that features an almost-flat asymptotic rotation curve $\propto r^{-1/18}$, which is expected to operate at approximately the same galactic scales as MOND.

gr-qc↗

On the relation between the canonical Hamilton-Jacobi equation and the De Donder-Weyl Hamilton-Jacobi formulation in general relativity

We discuss the relation between the canonical Hamilton-Jacobi theory and the De Donder-Weyl Hamilton-Jacobi theory known in the calculus of variations using the examples of a scalar field in curved space-time and general relativity. By restricting ourselves to the Gaussian coordinates we show how the canonical Hamilton-Jacobi equation of general relativity can be derived from the De Donder-Weyl Hamilton-Jacobi formulation of the Einstein equations.

gr-qc↗

Numerical Study on Space-Time Pulse Compression

A numerical study of the properties of Gaussian pulses propagating in planar waveguide under the combined effect of positive Kerr-type nonlinearity, diffraction in planar waveguides and anomalous or normal dispersion, is presented. It is demonstrated how the relative strength of dispersion and diffraction, the strength of nonlinearity and the initial spatial and temporal pulse chirps effect on the parameters of pulse compression, such as the maximal compression factor and the distance to the point of maximal compression.

physics.optics↗