2,946 research outputs found
A General Relativistic study of the neutrino path and calculation of minimum photosphere for different stars
A detailed general relativistic (GR) calculation of the neutrino path for a
general metric describing a rotating star is studied. We have calculated the
neutrino path along a plane, with the consideration that the neutrino does not
at any time leave the plane. The expression for the minimum photosphere radius
(MPR) is obtained and matched with the Schwarzschild limit. The MPR is
calculated for the stars with two different equations of state (EOS) each
rotating with two different velocities. The results shows that the MPR for the
hadronic star is much greater than the quark star and the MPR increases as the
rotational velocity of the star decreases. The MPR along the polar plane is
larger than that along the equatorial plane.Comment: 13 pages, 5 figures and 1 tabl
Quantum bound states for a derivative nonlinear Schrodinger model and number theory
A derivative nonlinear Schrodinger model is shown to support localized N-body
bound states for several ranges (called bands) of the coupling constant eta.
The ranges of eta within each band can be completely determined using number
theoretic concepts such as Farey sequences and continued fractions. For N > 2,
the N-body bound states can have both positive and negative momentum. For eta >
0, bound states with positive momentum have positive binding energy, while
states with negative momentum have negative binding energy.Comment: Revtex, 7 pages including 2 figures, to appear in Mod. Phys. Lett.
Partially Asymmetric Simple Exclusion Model in the Presence of an Impurity on a Ring
We study a generalized two-species model on a ring. The original model [1]
describes ordinary particles hopping exclusively in one direction in the
presence of an impurity. The impurity hops with a rate different from that of
ordinary particles and can be overtaken by them. Here we let the ordinary
particles hop also backward with the rate q. Using Matrix Product Ansatz (MPA),
we obtain the relevant quadratic algebra. A finite dimensional representation
of this algebra enables us to compute the stationary bulk density of the
ordinary particles, as well as the speed of impurity on a set of special
surfaces of the parameter space. We will obtain the phase structure of this
model in the accessible region and show how the phase structure of the original
model is modified. In the infinite-volume limit this model presents a shock in
one of its phases.Comment: Adding more references and doing minor corrections, 16 pages and 3
Eps figure
Multi-parameter deformed and nonstandard Yangian symmetry in integrable variants of Haldane-Shastry spin chain
By using `anyon like' representations of permutation algebra, which pick up
nontrivial phase factors while interchanging the spins of two lattice sites, we
construct some integrable variants of Haldane-Shastry (HS) spin chain. Lax
equations for these spin chains allow us to find out the related conserved
quantities. However, it turns out that such spin chains also possess a few
additional conserved quantities which are apparently not derivable from the Lax
equations. Identifying these additional conserved quantities, and the usual
ones related to Lax equations, with different modes of a monodromy matrix, it
is shown that the above mentioned HS like spin chains exhibit multi-parameter
deformed and `nonstandard' variants of Yangian symmetry.Comment: 18 pages, latex, no figure
Structural and electronic properties of oxygen defective and Se-doped p-type BiVO4(001) thin film for the applications of photocatalysis
This is the final version. Available on open access from Elsevier via the DOI in this record.There is another record in ORE for this publication: http://hdl.handle.net/10871/36011Monoclinic BiVO4 is being used as a photocatalyst due to its stability, cost-effectiveness, ease of synthesis, and narrow band gap. Although, the valence band maximum, VBM (∼−6.80 eV vs vacuum) of BiVO4 is well below the redox potential of water but having less positive conduction band minimum, CBM (−4.56 eV vs vacuum), responsible for its low efficiency. We have carried out a comprehensive periodic density functional theory (DFT) simulations for the pristine, Oxygen defective (Ov) and Se doped BiVO4, to engineer not only its CB edge position but the overall photocatalytic and charge carrier properties. Our theoretical method has nicely reproduced the experimental data of pristine BiVO4, which encouraged us to elaborate further its Ov and Se-doped characteristics. It is found that both the Ov (1% Oxygen vacancy) and Se-doped BiVO4 (1–2% Se) have ideal band edges, band gaps, and small effective masses of electrons and holes, responsible for high photocatalytic activities. Moreover, Se-doped BiVO4 behave as p-type semiconductor. Finally, the photocatalytic water-splitting behaviour of the selected surfaces were counterchecked with water interaction, where the strong water adsorption energy of about ∼−38 to −50 kcal/mol, confirms and predicts their higher efficiencies compared to that of parent BiVO4.The financial support was provided by Engineering and Physical Science Research Council, UK (EPSRC) under the research grant No EP/P510956/1
General Relativistic effects on the conversion of nuclear to two-flavour quark matter in compact stars
We investigate the General Relativistic (GR) effects on the conversion from
nuclear to two-flavour quark matter in compact stars, both static as well as
rotating. We find that GR effects lead to qualitative differences in rotating
stars, indicating the inadequacy of non-relativistic (NR) or even Special
Relativistic (SR) treatments for these cases.Comment: 4 pages, 4 figure
Structural and electronic properties of oxygen defective and Se-doped p-type BiVO4(001) thin film for the applications of photocatalysis
This is the final version. Available on open access from Elsevier via the DOI in this record.There is another record in ORE fro this publication: http://hdl.handle.net/10871/30528Monoclinic BiVO4 is being used as a photocatalyst due to its stability, cost-effectiveness, ease of synthesis, and narrow band gap. Although, the valence band maximum, VBM (∼−6.80 eV vs vacuum) of BiVO4 is well below the redox potential of water but having less positive conduction band minimum, CBM (−4.56 eV vs vacuum), responsible for its low efficiency. We have carried out a comprehensive periodic density functional theory (DFT) simulations for the pristine, Oxygen defective (Ov) and Se doped BiVO4, to engineer not only its CB edge position but the overall photocatalytic and charge carrier properties. Our theoretical method has nicely reproduced the experimental data of pristine BiVO4, which encouraged us to elaborate further its Ov and Se-doped characteristics. It is found that both the Ov (1% Oxygen vacancy) and Se-doped BiVO4 (1–2% Se) have ideal band edges, band gaps, and small effective masses of electrons and holes, responsible for high photocatalytic activities. Moreover, Se-doped BiVO4 behave as p-type semiconductor. Finally, the photocatalytic water-splitting behaviour of the selected surfaces were counterchecked with water interaction, where the strong water adsorption energy of about ∼−38 to −50 kcal/mol, confirms and predicts their higher efficiencies compared to that of parent BiVO4.Engineering and Physical Sciences Research Council (EPSRC
Exact spectrum and partition function of SU(m|n) supersymmetric Polychronakos model
By using the fact that Polychronakos-like models can be obtained through the
`freezing limit' of related spin Calogero models, we calculate the exact
spectrum as well as partition function of SU(m|n) supersymmetric Polychronakos
(SP) model. It turns out that, similar to the non-supersymmetric case, the
spectrum of SU(m|n) SP model is also equally spaced. However, the degeneracy
factors of corresponding energy levels crucially depend on the values of
bosonic degrees of freedom (m) and fermionic degrees of freedom (n). As a
result, the partition functions of SP models are expressed through some novel
q-polynomials. Finally, by interchanging the bosonic and fermionic degrees of
freedom, we obtain a duality relation among the partition functions of SP
models.Comment: Latex, 20 pages, no figures, minor typos correcte
Adapting buildings to climate change
The interdependence and feedback between climate impacts mitigation and adaptation to the inevitable changes in climate are the key challenges for the built environment in the coming decades. These challenges are more pronounced in the interface between science and society, in which scientific knowledge and evidence are transformed into policy actions. This editorial looks at current and growing evidence base on the impacts of climate change and the means to adapt buildings, as well as the interface between policies and evidence base while summarising the contributions to this special issue
Adapting buildings to climate change
The interdependence and feedback between climate impacts mitigation and adaptation to the inevitable changes in climate are the key challenges for the built environment in the coming decades. These challenges are more pronounced in the interface between science and society, in which scientific knowledge and evidence are transformed into policy actions. This editorial looks at current and growing evidence base on the impacts of climate change and the means to adapt buildings, as well as the interface between policies and evidence base while summarising the contributions to this special issue
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