1,145 research outputs found
On the one-loop correction of "phi^4" theory in higher dimensions
We have considered phi^4 theory in higher dimensions. Using functional
diagrammatic approach, we computed the one-loop correction to effective
potential of the scalar field in five dimensions. It is shown that phi^4 theory
can be regularised in five dimensions. Temperature dependent one-loop
correction and critical temperature T_c are computed and T_c depends on the
fundamental scale M of the theory. A brief discussion of symmetry restoration
is also presented. The nature of phase transitions is examined and is of second
orderComment: 8 pages, 5 figures. To appear in IJMP
Dvali-Gabadadze-Porrati Cosmology in Bianchi I brane
The dynamics of Dvali-Gabadadze-Porrati Cosmology (DGP) braneworld with an
anisotropic brane is studied. The Friedmann equations and their solutions are
obtained for two branches of anisotropic DGP model. The late time behavior in
DGP cosmology is examined in the presence of anisotropy which shows that
universe enters a self-accelerating phase much later compared to the isotropic
case. The acceleration conditions and slow-roll conditions for inflation are
obtained
Bulk scalar field in DGP braneworld cosmology
We investigated the effects of bulk scalar field in the braneworld
cosmological scenario. The Friedmann equations and acceleration condition in
presence of the bulk scalar field for a zero tension brane and cosmological
constant are studied. In DGP model the effective Einstein equation on the brane
is obtained with bulk scalar field. The rescaled bulk scalar field on the brane
in the DGP model behaves as an effective four dimensional field, thus standard
type cosmology is recovered. In present study of the DGP model, the late-time
accelerating phase of the universe can be explained .Comment: 10 pages, to appear in JCA
Seasonal Variation of Groundwater Quality for Irrigational uses in Gadilam River Basin, Tamil Nadu, India
The present research work pertains to the Gadilam river basin groundwater quality for irrigation uses with respect to the Archaean formation, the Quaternary formation, the Tertiary formation and the Cretaceous formation. Experiments were carried out for two seasons (rainy season and summer season) for two successive years (November 2018 and June 2019). Overall, 120 groundwater samples were collected from the Gadilam river basin, excluding the reserved forest area. The 50 samples were collected from the Archaean formation, 34 samples from the Quaternary formation, and 35 samples from the Tertiary Formation. The remaining sample is from the Cretaceous formation. Based on the obtained analysed data, the following agricultural water quality parameters were calculated using the following expressions: The irrigational quality parameters are used, such as sodium percentage (Na%), sodium adsorption ratio (SAR), Kelly’s ratio (KR), permeability index (PI), magnesium ratio (MR), residual sodium carbonate (RSC), and potential salinity (PS) are calculated and assessed for irrigation purposes
- …