arXiv subjects

Mladen Martinis

Publications and source records attributed to Mladen Martinis.

5 recordsLinked to original sources

arXiv2011

Application of Gauss' Law in Acoustics

Practical application of Gauss' law in acoustics is not a very well known method. However, any inverse square law behavior can be formulated in the way similar to Gauss' law, which allows us to extend the same principle to sound waves propagation. We show in this paper how the acoustic power of sound source can be related to the sound intensity flow through a given surface by means of the Gauss' law. Several different sound-source shapes, important in practical applications, are analyzed by means of the Gauss' law. A suitable choice of the Gaussian surface allows us to obtain the simple and straightforward method for calculating the sound intensity distribution in space.

physics.flu-dyn↗

arXiv2010

Is exponential metric a natural space-time metric of Newtonian gravity ?

We show how Newtonian gravity with effective (actually observed) masses, obeying the mass-energy relation of special relativity, can explain all observations used to test General relativity. Dynamics of a gravitationally coupled binary system is considered in detail, and the effective masses of constituents are determined. Interpreting our results in terms of motion in a curved space-time background, we are led, using the Lagrangian formalism, to consider the exponential metric as a natural space-time metric of Newtonian gravity.

gr-qc↗

arXiv2004

Quantum Horizons and Space-Time Non-Commutativity

We study dynamics of a scalar field in the near-horizon region described by a static Klein-Gordon operator which is the Hamiltonian of the system. The explicite construction of a time operator near-horizon is given and its self-adjointness discussed.

gr-qc↗

arXiv2004

Charge and Isospin Fluctuations in High Energy pp-Collisions

Charge and isospin event-by-event fluctuations in high-energy pp-collisions are predicted within the Unitary Eikonal Model, in particular the fluctuation patterns of the ratios of charged-to-charged and neutral-to-charged pions. These fluctuations are found to be sensitive to the presence of unstable resonances, such as $ρ$ and $ω$ mesons. We predict that the charge-fluctuation observable $D_{UEM}$ should be restricted to the interval $8/3\le D_{UEM}\le 4$ depending on the $ρ/π$ production ratio. Also, the isospin fluctuations of the DCC-type of the ratio of neutral-to-charged pions are suppressed if pions are produced together with $ρ$ mesons.

hep-ph↗

arXiv2003

Disoriented Chiral Condensate and Charge-Neutral Particle Fluctuations in Heavy Ion Collisions

The posibility of large charge and isospin fluctuations in high-energy heavy ion-collisions is studied within the framework of the nonlinear $σ$-model with quark degrees of freedom. The multipion exchange potential between two quarks is derived. It is shown that the soft chiral pion bremsstralung leads to anomalously large fluctuations in the ratio of neutral to charged pions, predicted by the formation of a disoriented chiral condensate (DCC). The factorization property of the scattering amplitude in the impact parameter space of the leading two-nucleon system is used to study semiclassical production of pions in the central region. We show that the DCC-type fluctuations are suppressed if a large number of pions are produced in $ρ$-type clusters. Our conclusion is supported through the calculation of two pion correlation parameters as a function of the $ρ$-to-$π$ ratio.

nucl-th↗