5,554 research outputs found

    Boundary breathers in the sinh-Gordon model

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    We present an investigation of the boundary breather states of the sinh-Gordon model restricted to a half-line. The classical boundary breathers are presented for a two parameter family of integrable boundary conditions. Restricting to the case of boundary conditions which preserve the \phi --> -\phi symmetry of the bulk theory, the energy spectrum of the boundary states is computed in two ways: firstly, by using the bootstrap technique and subsequently, by using a WKB approximation. Requiring that the two descriptions of the spectrum agree with each other allows a determination of the relationship between the boundary parameter, the bulk coupling constant, and the parameter appearing in the reflection factor derived by Ghoshal to describe the scattering of the sinh-Gordon particle from the boundary.Comment: 16 pages amslate

    Carbon Monoxide Screening in Pregnancy: An Evaluation Study of a Plymouth Pilot Intervention

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    This report provides an analysis and evaluation of a National Institute for Health and Care Excellence (NICE) recommended pilot intervention which was designed to identify pregnant women exposed to carbon monoxide due to cigarette smoke and refers them to local stop smoking services (LSSS). The pilot intervention was carried out by community midwives working in two areas of Plymouth. The city has areas of social and health inequalities and the study drew on populations from a socially deprived neighbourhood and a socially affluent area. The pilot was instigated following new NICE guidance recommending that all women attending initial ante natal booking appointments with their community midwives be offered a Carbon Monoxide (CO) breath analyser screening to determine their smoking status and or exposure to other forms of CO. This evaluation study identifies the benefits and barriers associated with the implementation of the CO screening pilot. In particular, our aims were to explore any detrimental impact on the relationship between women and their community midwives, identify the impact on midwives in terms of time and resources, reveal the responses and acceptability or otherwise of the screening as perceived and experienced by the women being asked to participate during the booking appointment and finally to evaluate the success of the intervention overall in relation to the numbers of referrals made to Plymouth’s LSSS. A further aim was explore any differences in the two socio demographic areas. We adopted a mixed methods approach involving four focus group interviews with 23 midwives, a survey posted to the 258 women who attended initial antenatal booking appointments in the study areas, an online version of the survey to ascertain the views and experiences of pregnant women and new mothers nationally and an interrogation of an internet forum discussion board for mothers. A two page questionnaire consisting of 12 questions was designed and posted to women who attended the booking appointment with the midwife during the three month pilot period and the same survey was made available online. Questions were designed to elicit women’s views about the information given by the midwife in relation to the screening, whether they had agreed to participate in the CO screening process, their experiences and views about offering CO screening to pregnant women and their smoking status and those of other household members. Of the 258 questionnaires posted to women who had attended the clinic during the pilot intervention 40 completed responses were returned representing a 15.5% response rate. Only 4 responses were received from the online survey posting but an additional 484 comments posted on the Mumsnet website discussion board were analysed. Our findings show that in general there was a high degree of acceptability for the intervention. Midwives and their clients were generally in support of the screening being offered to all pregnant women. However, this support was dependent on a number of contextual factors. Women wanted to be properly informed about the screening and midwives wanted to be kept informed about the effects of the intervention on women’s smoking cessation. Initial and ongoing training of midwives in utilising the protocol and in instructing women to correct use the monitor was also very important. Trust was revealed to be a very important aspect of the relationship between women and their midwives. Some women felt that the CO screening was being used just to check whether or not they were smokers and some midwives also worried about the possible negative effects the CO screening may have on their relationships with women

    The sine-Gordon model with integrable defects revisited

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    Application of our algebraic approach to Liouville integrable defects is proposed for the sine-Gordon model. Integrability of the model is ensured by the underlying classical r-matrix algebra. The first local integrals of motion are identified together with the corresponding Lax pairs. Continuity conditions imposed on the time components of the entailed Lax pairs give rise to the sewing conditions on the defect point consistent with Liouville integrability.Comment: 24 pages Latex. Minor modifications, added comment

    Form factors of boundary exponential operators in the sinh-Gordon model

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    Using the recently introduced boundary form factor bootstrap equations, the form factors of boundary exponential operators in the sinh-Gordon model are constructed. The ultraviolet scaling dimension and the normalization of these operators are checked against previously known results. The construction presented in this paper can be applied to determine form factors of relevant primary boundary operators in general integrable boundary quantum field theories.Comment: 22 pages, LaTeX2e fil

    Moyal Brackets in M-Theory

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    The infinite limit of Matrix Theory in 4 and 10 dimensions is described in terms of Moyal Brackets. In those dimensions there exists a Bogomol'nyi bound to the Euclideanized version of these equations, which guarantees that solutions of the first order equations also solve the second order Matrix Theory equations. A general construction of such solutions in terms of a representation of the target space co-ordinates as non-local spinor bilinears, which are generalisations of the standard Wigner functions on phase space, is given.Comment: 10 pages, Latex, no figures. References altered, typos correcte

    Free Field Realization of Vertex Operators for Level Two Modules of Uq(sl(2)^)U_q(\hat{sl(2)})

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    Free field relization of vertex operators for lvel two modules of Uq(sl(2)^)U_q(\hat{sl(2)}) is shown through the free field relization of the modules given by Idzumi in Ref.[4,5]. We constructed types I and II vertex operators when the spin of the addociated evaluation modules is 1/2 and typ II's for the spin 1.Comment: 15 pages, to appear in J.Phys.A:Math and Genera

    Boundary Reflection Matrix for D4(1)D_4^{(1)} Affine Toda Field Theory

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    We present one loop boundary reflection matrix for d4(1)d_4^{(1)} Toda field theory defined on a half line with the Neumann boundary condition. This result demonstrates a nontrivial cancellation of non-meromorphic terms which are present when the model has a particle spectrum with more than one mass. Using this result, we determine uniquely the exact boundary reflection matrix which turns out to be \lq non-minimal' if we assume the strong-weak coupling \lq duality'.Comment: 14 pages, Late
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