Browsing by Autor "M. Nowakowski"

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Extracting information from the gravitational redshift of compact rotating objects
(Springer Nature, 2010) Paul D. Nuñez; M. Nowakowski
Extracting Information from the Gravitational Redshift of Compact Rotating Objects
(Cornell University, 2008) Paul D. Nuñez; M. Nowakowski
When rotation is not taken into account, the measurement of the Gravitational Redshift can provide unique information about the compactness ($M/R$) of the star. Rotation alters the gravitational redshift rendering thereby a unique determination of the compactness parameter impossible. Nevertheless, it can be shown that by using some theoretical input, useful information on, say, the radii of compact rotating objects can still be extracted. Moreover, by measuring the gravitational redshift one can infer the maximum angular velocity of the object. As it is well known, the minimum observed periods of rotation are found in millisecond pulsars. Here we show that millisecond periods are actually a semi-theoretical limit that can be found by General Relativistic arguments corresponding to the maximum angular velocity. We apply our method to compact objects such as pulsars, white dwarfs and neutron stars.
Lorentz Contracted Proton
(Cornell University, 2014) D. Bedoya Fierro; N. G. Kelkar; M. Nowakowski
The proton charge and magnetization density distributions can be related to the well known Sachs electromagnetic form factors $G_{E,M}({\bm q}^{2})$ through Fourier transforms, only in the Breit frame. The Breit frame however moves with relativistic velocities in the Lab and a Lorentz boost must be applied to the form factors before extracting the static properties of the proton from the corresponding densities. Apart from this, the Fourier transform relating the densities and form factors is inherently a non-relativistic expression. We show that the relativistic corrections to it can be obtained by extending the standard Breit equation to higher orders in its $1/c^2$ expansion. We find that the inclusion of the above corrections reduces the size of the proton determined from electron proton scattering data. Indeed the central value of the latest proton radius of $r_p = 0.879$ fm as determined from e-p scattering changes to $r_p = 0.8404$ fm after applying corrections.
Opportunities and problems in determining proton and light nuclear radii
(2014) N. G. Kelkar; M. Nowakowski; D. Bedoya Fierro
Quantum Corrections to the Decay Law in Flight
(RELX Group (Netherlands), 2024) Diego Fernando Ramirez Jimenez; Andrés Felipe Guerrero Parra; N. G. Kelkar; M. Nowakowski
The repulsive nature of naked singularities from the point of view of Quantum Mechanics
(Springer Science+Business Media, 2011) Davide Batic; Denise A. Chin; M. Nowakowski
Virial theorem and gravitational equilibrium with a cosmological constant
(2001) M. Nowakowski; Juan Carlos Sanabria; A. Garcı́a
Starting from the Newtonian limit of Einstein's equations in the presence of a positive cosmological constant, we obtain a new version of the virial theorem and a condition for gravitational equilibrium. Such a condition takes the form ρ &gt; λρvac, where ρ is the mean density of an astrophysical system (e.g. galaxy, galaxy cluster or supercluster), λ is a quantity which depends only on the shape of the system, and ρvac is the vacuum density. We conclude that gravitational stability might be infiuenced by the presence of Λ depending strongly on the shape of the system.