30,281 research outputs found
On the Fock space for nonrelativistic anyon fields and braided tensor products
We realize the physical N-anyon Hilbert spaces, introduced previously via
unitary representations of the group of diffeomorphisms of the plane, as N-fold
braided-symmetric tensor products of the 1-particle Hilbert space. This
perspective provides a convenient Fock space construction for nonrelativistic
anyon quantum fields along the more usual lines of boson and fermion fields,
but in a braided category. We see how essential physical information is thus
encoded. In particular we show how the algebraic structure of our anyonic Fock
space leads to a natural anyonic exclusion principle related to intermediate
occupation number statistics, and obtain the partition function for an
idealised gas of fixed anyonic vortices.Comment: Added some references, more explicit formulae for the discrete case
and remark on partition function. 25 pages latex, no figure
Rare Earth Doping and Effective Band-Convergence in SnTe for Improved Thermoelectric Performance
Thermoelectric performance of SnTe has been found to enhance with isovalent
doping of alkaline and transition metal elements where most of these elements
have solubility of less than 13%. We propose a strategy of doping rare earth
element Yb to enhance the thermoelectric performance of SnTe. With heavy atomic
mass and strong spin-orbit coupling, even the mild doping of Yb (~ 5%) is
enough to create a degeneracy via band-convergence which enhances the density
of states near Fermi level and improve overall performance. Our transport data
and first-principles calculations corroborate that nearly 5% Yb is an efficient
dopant to achieve thermoelectric response which is equivalent to 9% of Mn
doping. The results are useful for understanding the environment-friendly
thermoelectric SnTe
Rotating membranes on G_2 manifolds, logarithmic anomalous dimensions and N=1 duality
We show that the behaviour found for long strings rotating
on may be reproduced by membranes rotating on and on a warped M-theory solution. We go on to obtain rotating
membrane configurations with the same relation on
holonomy backgrounds that are dual to gauge theories in four
dimensions. We study membrane configurations on holonomy backgrounds
systematically, finding various other Energy-Charge relations. We end with some
comments about strings rotating on warped backgrounds.Comment: 1+44 pages. Latex. No figures. Minor corrections to make all membrane
configurations consistent. One configuration is now noncompac
Type IIA Orientifold Limit of M-Theory on Compact Joyce 8-Manifold of Spin(7)-Holonomy
We show that M-theory compactified on a compact Joyce 8-manifold of
-holonomy, which yields an effective theory in with = 1
supersymmetry, admits at some special points in it moduli space a description
in terms of type IIA theory on an orientifold of compact Joyce 7-manifold of
-holonomy. We find the evidence in favour of this duality by computing the
massless spectra on both M-thory side and type IIA side. For the latter, we
compute the massless spectra by going to the orbifold limit of the Joyce
7-manifold.Comment: 26 pages, 2 eps figures, Latex file, two references and one footnote
added, corrected some typo
Outage Analysis for SWIPT-Enabled Two-Way Cognitive Cooperative Communications
In this paper, we study a cooperative cognitive radio network (CCRN) where
the secondary user-transmitter (SU-Tx) assists bi-directional communication
between a pair of primary users (PUs) following the principle of two-way
relaying. In return, it gets access to the spectrum of the PUs to enable its
own transmission to SU-receiver (SU-Rx). Further, in order to support
sustainable operation of the network, SU-Tx is assumed to harvest energy from
the RF signals received from the PUs, using the technique of simultaneous
wireless information and power transfer (SWIPT). Assuming a decode-and-forward
behaviour and power-splitting based relaying protocol at SU-Tx, closed form
expressions for outage probability of PU and SU are obtained. Simulation
results validate our analytical results and illustrate spectrum-efficiency and
energy-efficiency advantages of the proposed system over one-way relaying.Comment: 15 pages, 5 figures, Submitted to IEEE Transactions on Vehicular
Technolog
Features of deSitter Vacua in M-Theory
We compute the masses of all moduli in the unstable deSitter vacua arising in
the toy model of cosmological M-theory flux compactifications on the G2
holonomy manifolds of [1]. The slow-roll parameters in the tachyonic directions
are shown to be too large to be useful for conventional models of inflation.
However, it appears that we can find fast roll regimes which could, under
certain conditions, account for the current dark energy driven accelerated
expansion of the universe.Comment: 14 pages, 1 figur
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