260 research outputs found
Gravitacijsko polje mirnog globalnog monopola u višoj dimenziji
In this paper, we study the gravitational field of a non-stationary global monopole in higher dimension by using field-theoretic energy-momentum tensors for monopole configuration. The solutions are obtained using the functional separability of the metric coefficients. We have shown that the monopole exerts attractive gravitational effects on test particles.U ovom radu proučavamo gravitacijsko polje mirnog globalnog monopola kojega oblikujemo u više-dimenzijskom prostoru primjenom tenzora energije-impulsa teorije polja. Rješenja postižemo rabeći funkcijsku razdvojivost metričkih koeficijenata. Pokazujemo da monopol proizvodi privlačan gravitacijski učinak
Gravitacijsko polje mirnog globalnog monopola u višoj dimenziji
In this paper, we study the gravitational field of a non-stationary global monopole in higher dimension by using field-theoretic energy-momentum tensors for monopole configuration. The solutions are obtained using the functional separability of the metric coefficients. We have shown that the monopole exerts attractive gravitational effects on test particles.U ovom radu proučavamo gravitacijsko polje mirnog globalnog monopola kojega oblikujemo u više-dimenzijskom prostoru primjenom tenzora energije-impulsa teorije polja. Rješenja postižemo rabeći funkcijsku razdvojivost metričkih koeficijenata. Pokazujemo da monopol proizvodi privlačan gravitacijski učinak
Bezvakuumski globalni monopol u Einstein-Cartanovoj teoriji
We analyze the gravitational field of vacuumless global monopole in the context of Einstein-Cartan theory under the weak field assumption of the field equations. It has been shown that global monopole exerts attractive gravitational force on a test particle. This effect is absent in general relativity.Analiziramo gravitacijsko polje bezvakuumskog globalnog monopola u okviru Einstein–Cartanove teorije, uzevši pretpostavku slabog polja u jednadžbama polja. Pokazuje se da globalni monopol proizvodi privlačnu gravitacijsku silu na ispitnu česticu. Takvog učinka nema u općoj teoriji relativnosti
Bezvakuumski globalni monopol u Einstein-Cartanovoj teoriji
We analyze the gravitational field of vacuumless global monopole in the context of Einstein-Cartan theory under the weak field assumption of the field equations. It has been shown that global monopole exerts attractive gravitational force on a test particle. This effect is absent in general relativity.Analiziramo gravitacijsko polje bezvakuumskog globalnog monopola u okviru Einstein–Cartanove teorije, uzevši pretpostavku slabog polja u jednadžbama polja. Pokazuje se da globalni monopol proizvodi privlačnu gravitacijsku silu na ispitnu česticu. Takvog učinka nema u općoj teoriji relativnosti
Spherical collapse of a heat conducting fluid in higher dimensions without horizon
We consider a scenario where the interior spacetime,described by a heat
conducting fluid sphere is matched to a Vaidya metric in higher
dimensions.Interestingly we get a class of solutions, where following heat
radiation the boundary surface collapses without the appearance of an event
horizon at any stage and this happens with reasonable properties of matter
field.The non-occurrence of a horizon is due to the fact that the rate of mass
loss exactly counterbalanced by the fall of boundary radius.Evidently this
poses a counter example to the so-called cosmic censorship hypothesis.Two
explicit examples of this class of solutions are also given and it is observed
that the rate of collapse is delayed with the introduction of extra
dimensions.The work extends to higher dimensions our previous investigation in
4D.Comment: 6 page
Estimation of inherent governor dead-band and regulation using unscented Kalman filter
The inclusion of the governor droop and dead-band in dynamic models helps to reproduce the measured frequency response accurately and is a key aspect of model validation. Often, accurate and detailed turbine-governor information are not available for various units in an area control centre. The uncertainty in the droop also arise from the nonlinearity due to the governor valves. The droop and deadband are required to tune the secondary frequency bias factors, and to determine the primary frequency reserve. Earlier research on droop estimation did not adequately take into account the effect of dead-band and other nonlinearities. In this paper, unscented Kalman filter is used in conjunction with continuously available measurements to estimate the governor droop and the dead-band width. The effectiveness of the approach is demonstrated through simulation
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