119554385
TBA-like equations and Casimir effect in (non-)perturbative AdS/CFT
A bstractWe consider high spin, s, long twist, L, operators in the planar $ \mathcal{N}=4 $ SYM at strong coupling. Precisely, we compute the minimal anomalous dimensions (from asymptotic Bethe Ansatz) for large ’t Hooft coupling λ to the lowest order of the (string) scaling variable $ \ell \sim L/\left( {\ln\,S\sqrt{\lambda }} \right) $ with GKP string size ~ $ \ln\,S\equiv 2\ln \left( {s/\sqrt{\lambda }} \right) $. At the leading order (ln S) · ℓ2, we can confirm the O(6) non-linear sigma model description for this bulk term, without boundary term (ln S)0. Going further, we derive, extending the O(6) regime, the exact effect of the size finiteness. In particular, we compute, at all loops, the first Casimir correction ℓ0/ ln S (in terms of the infinite size O(6) NLSM), which reveals only one massless mode (out of five), as predictable once the O(6) description has been extended. Consequently, upon comparing with string theory expansion, at one loop our findings agree for large twist, while reveal for negligible twist, already at this order, the appearance of wrapping. At two loops, as well as for next loops and orders, we can produce predictions, which may guide future string computations.
9495374
CENTRAL EXTENSIONS OF CLASSICAL AND QUANTUM Q-VIRASORO ALGEBRAS
We investigate the central extensions of the q-deformed (classical and quantum) Virasoro algebras constructed from the elliptic quantum algebra Aq,p(sl(N))c. After establishing the expressions of the cocycle conditions, we solve them, both in the classical and in the quantum case (for sl(2)). We find that the consistent central extensions are much more general that those found previously in the literature.
18236433
The Elliptic Scattering Theory of the 1/2-XYZ and Higher Order Deformed Virasoro Algebras
Abstract.Bound state excitations of the spin 1/2-XYZ model are considered inside the Bethe Ansatz framework by exploiting the equivalent Non-Linear Integral Equations. Of course, these bound states go to the sine-Gordon breathers in the suitable limit and therefore the scattering factors between them are explicitly computed by inspecting the corresponding Non-Linear Integral Equations. As a consequence, abstracting from the physical model the Zamolodchikov-Faddeev algebra of two n-th elliptic breathers defines a tower of n-order Deformed Virasoro Algebras, reproducing the n = 1 case the usual well-known algebra of Shiraishi-Kubo-Awata-Odake [1].Communicated by Vincent Rivasseau
120458416
Unitary group representations in fock spaces with generalized exchange properties
We investigate the notion of secondR-quantization - a suitable deformation of the standard second quantization which properly takes into account the nontrivial exchange properties characterizing generalized statistics. We also perform theR-quantization of a class of unitary one-particle representations relevant for the description of symmetries. The Euclidean covariance of anyons is analyzed within this context.
120678958
Fock representations of exchange algebras with involution
An associative algebra AR with exchange properties generalizing the canonical (anti)commutation relations is considered. We introduce a family of involutions in AR and construct the relative Fock representations, examining the positivity of the metric. As an application of the general results, we rigorously prove unitarity of the scattering operator of integrable models in 1+1 space-time dimensions. In this context the possibility of adopting various involutions in the Zamolodchikov–Faddeev algebra is also explored.
18478779
A braided Yang–Baxter algebra in a theory of two coupled lattice quantum KdV: algebraic properties and ABA representations
A generalization of the Yang–Baxter algebra is found in quantizing the monodromy matrix of two (m)KdV equations discretized on a space lattice. This braided Yang–Baxter equation still ensures that the transfer matrix generates operators in involution which form the Cartan sub-algebra of the braided quantum group. Representations diagonalizing these operators are described through relying on an easy generalization of algebraic Bethe ansatz techniques. The conjecture that this monodromy matrix algebra leads, in the cylinder continuum limit, to a perturbed minimal conformal field theory description is analysed and supported.
122836697
CVD diamond films as photon detectors
Abstract We present an overview of our research on Chemical Vapour Deposited (CVD) diamond films as photon detectors. Samples are grown in our laboratories using three different methods: microwave plasma enhanced CVD (MWPECVD), DC glow discharge CVD (DCGDCVD) and hot filament CVD (HFCVD). We present the photoelectrical properties of these samples having contacts in planar and sandwich configuration, taking into account the roles of material microstructure and electrical configuration. Their photoresponse has been measured in the whole visible–near UV spectral range with the aim to characterize their UV selectivity and to evaluate their gap-state density.