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arXivMonstrous StringString Duality S. Chaudhuri, D. A. Lowe 19951231 We analyze the general class of supersymmetry preserving orbifolds of strong/weak Type IIA/heterotic dual pairs in six dimensions and below. A unified treatment is given by considering compactification to two spacetime dimensions and constructing orbifolds by subgroups of the FischerGreiss monster, utilizing the moonshine results of Conway and Norton. Duality requires nontrivial RamondRamond fluxes on the Type IIA side which are localized at the fixed points. Further orbifolding by (1)^{F_L} gives examples of new four dimensional N=2 Type IIA vacua which are not conformal field theory backgrounds.
Subject Source arXiv URL https://arxiv.org/abs/hepth/9512226view Article Title Monstrous StringString DualityAuthors S. Chaudhuri; D. A. LoweAbstract We analyze the general class of supersymmetry preserving orbifolds of strong/weak Type IIA/heterotic dual pairs in six dimensions and below. A unified treatment is given by considering compactification to two spacetime dimensions and constructing orbifolds by subgroups of the FischerGreiss monster, utilizing the moonshine results of Conway and Norton. Duality requires nontrivial RamondRamond fluxes on the Type IIA side which are localized at the fixed points. Further orbifolding by (1)^{F_L} gives examples of new four dimensional N=2 Type IIA vacua which are not conformal field theory backgrounds.Is Part Of Nucl.Phys.B469:2136,1996 19951231 Identifier ISSN: DOI 10.1016/05503213(96)001319Category hepthLicense 
arXivWoven Braids and their Closures Jan A. Kneissler 19951231 A special class of braids, called woven, is introduced and it is shown that every conjugation class of the braid group contains woven braids. In consequence, links can be presented as plats or closures of woven braids. Restricting on knots, we get the 'woven version' of the wellknown theorem of Markov, giving moves that are capable of producing all woven braids with equivalent closures. As corollary we obtain that a link in which each component is dyed with at least two colours can be projected onto a plane without crossing strands of the same colour. Finally a table of minimal woven braids for all nine crossing knots is appended.
Subject 수학 Source arXiv URL https://arxiv.org/abs/qalg/9512033view Article Title Woven Braids and their ClosuresAuthors Jan A. KneisslerAbstract A special class of braids, called woven, is introduced and it is shown that every conjugation class of the braid group contains woven braids. In consequence, links can be presented as plats or closures of woven braids. Restricting on knots, we get the 'woven version' of the wellknown theorem of Markov, giving moves that are capable of producing all woven braids with equivalent closures. As corollary we obtain that a link in which each component is dyed with at least two colours can be projected onto a plane without crossing strands of the same colour. Finally a table of minimal woven braids for all nine crossing knots is appended.Is Part Of 19951231 Identifier ISSN: Category qalg math.QALicense 
arXivThe Master Field in Generalised $QCD_2$ Rajesh Gopakumar 19951231 As an illustration of the formalism of the master field we consider generalised $QCD_2$. We show how Wilson Loop averages for an arbitrary contour can be computed explicitly and with some ease. A generalised Hopf equation is shown to govern the behaviour of the eigenvalue density of Wilson loops. The collective field description of the theory is therefore deduced. Finally, the nontrivial master gauge field and field strengths are obtained. These results do not seem easily accessible with conventional means.
Subject Source arXiv URL https://arxiv.org/abs/hepth/9512225view Article Title The Master Field in Generalised $QCD_2$Authors Rajesh GopakumarAbstract As an illustration of the formalism of the master field we consider generalised $QCD_2$. We show how Wilson Loop averages for an arbitrary contour can be computed explicitly and with some ease. A generalised Hopf equation is shown to govern the behaviour of the eigenvalue density of Wilson loops. The collective field description of the theory is therefore deduced. Finally, the nontrivial master gauge field and field strengths are obtained. These results do not seem easily accessible with conventional means.Is Part Of Nucl.Phys. B471 (1996) 246262 19951231 Identifier ISSN: DOI 10.1016/05503213(96)001915Category hepthLicense 
arXivLoop Variables and Gauge Invariant Interactions of Massive Modes in String Theory B. Sathiapalan 19951231 The loop variable approach used earlier to obtain free equations of motion for the massive modes of the open string, is generalized to include interaction terms. These terms, which are polynomial, involve only modes of strictly lower mass. Considerations based on operator product expansions suggest that these equations are particular truncations of the full string equations. The method involves broadening the loop to a band of finite thickness that describes all the different interacting strings. Interestingly, in terms of these variables, the theory appears noninteracting.
Subject Source arXiv URL https://arxiv.org/abs/hepth/9512224view Article Title Loop Variables and Gauge Invariant Interactions of Massive Modes in String TheoryAuthors B. SathiapalanAbstract The loop variable approach used earlier to obtain free equations of motion for the massive modes of the open string, is generalized to include interaction terms. These terms, which are polynomial, involve only modes of strictly lower mass. Considerations based on operator product expansions suggest that these equations are particular truncations of the full string equations. The method involves broadening the loop to a band of finite thickness that describes all the different interacting strings. Interestingly, in terms of these variables, the theory appears noninteracting.Is Part Of Mod.Phys.Lett. A11 (1996) 571586 19951231 Identifier ISSN: DOI 10.1142/S0217732396000606Category hepthLicense 
arXivThe Design and Experimental Analysis of Algorithms for Temporal Reasoning P. vanBeek, D. W. Manchak 19951231 Many applications  from planning and scheduling to problems in molecular biology  rely heavily on a temporal reasoning component. In this paper, we discuss the design and empirical analysis of algorithms for a temporal reasoning system based on Allen's influential intervalbased framework for representing temporal information. At the core of the system are algorithms for determining whether the temporal information is consistent, and, if so, finding one or more scenarios that are consistent with the temporal information. Two important algorithms for these tasks are a path consistency algorithm and a backtracking algorithm. For the path consistency algorithm, we develop techniques that can result in up to a tenfold speedup over an already highly optimized implementation. For the backtracking algorithm, we develop variable and value ordering heuristics that are shown empirically to dramatically improve the performance of the algorithm. As well, we show that a previously suggested reformulation of the backtracking search problem can reduce the time and space requirements of the backtracking search. Taken together, the techniques we develop allow a temporal reasoning component to solve problems that are of practical size.
Subject Source arXiv URL https://arxiv.org/abs/cs/9601101view Article Title The Design and Experimental Analysis of Algorithms for Temporal ReasoningAuthors P. vanBeek; D. W. ManchakAbstract Many applications  from planning and scheduling to problems in molecular biology  rely heavily on a temporal reasoning component. In this paper, we discuss the design and empirical analysis of algorithms for a temporal reasoning system based on Allen's influential intervalbased framework for representing temporal information. At the core of the system are algorithms for determining whether the temporal information is consistent, and, if so, finding one or more scenarios that are consistent with the temporal information. Two important algorithms for these tasks are a path consistency algorithm and a backtracking algorithm. For the path consistency algorithm, we develop techniques that can result in up to a tenfold speedup over an already highly optimized implementation. For the backtracking algorithm, we develop variable and value ordering heuristics that are shown empirically to dramatically improve the performance of the algorithm. As well, we show that a previously suggested reformulation of the backtracking search problem can reduce the time and space requirements of the backtracking search. Taken together, the techniques we develop allow a temporal reasoning component to solve problems that are of practical size.Is Part Of Journal of Artificial Intelligence Research, Vol 4, (1996), 118 19951231 Identifier ISSN: Category cs.AILicense 
arXivSpherical maximal operators on radial functions Andreas Seeger, Stephen Wainger, James Wright... more(3) 19951231 Let $A_tf(x)=\int f(x+ty)d\sigma(y)$ denote the spherical means in $\Bbb R^d$ ($d\sigma$ is surface measure on $S^{d1}$, normalized to $1$). We prove sharp estimates for the maximal function $M_E f(x)=\sup_{t\in E}A_tf(x)$ where $E$ is a fixed set in $\Bbb R^+$ and $f$ is a {\it radial} function $\in L^p(\Bbb R^d)$. Let $p_d=d/(d1)$ (the critical exponent of Stein's maximal function). For the cases (i) $p
Subject 수학 Source arXiv URL https://arxiv.org/abs/math/9601220view Article Title Spherical maximal operators on radial functionsAuthors Andreas Seeger; Stephen Wainger; James WrightAbstract Let $A_tf(x)=\int f(x+ty)d\sigma(y)$ denote the spherical means in $\Bbb R^d$ ($d\sigma$ is surface measure on $S^{d1}$, normalized to $1$). We prove sharp estimates for the maximal function $M_E f(x)=\sup_{t\in E}A_tf(x)$ where $E$ is a fixed set in $\Bbb R^+$ and $f$ is a {\it radial} function $\in L^p(\Bbb R^d)$. Let $p_d=d/(d1)$ (the critical exponent of Stein's maximal function). For the cases (i) $pIs Part Of 19951231 Identifier ISSN: Category math.FALicense 
arXivBinary Evolution of Type Ia Supernovae J. Craig Wheeler 19951230 Observations of Type Ia supernovae (SN~Ia) combined with modeling of dynamics, light curves and spectra continue to point to the difficult conclusion that SN~Ia result from degenerate ignition in a carbon/oxygen white dwarf of the Chandrasekhar mass. Such a model accounts well for the ``normal" SN~Ia and for the observed dispersion exemplified by the light curve amplitudeshape relation. The criterion that the white dwarfs involved in this process grow to nearly 1.4 Msun continues to provide a great challenge to understanding the binary stellar evolution involved. The socalled ``supersoft Xray sources" may provide an important new population of SN~Ia progenitors. Other techniques are being developed that may constrain the binary evolution.
Subject Source arXiv URL https://arxiv.org/abs/astroph/9512171view Article Title Binary Evolution of Type Ia SupernovaeAuthors J. Craig WheelerAbstract Observations of Type Ia supernovae (SN~Ia) combined with modeling of dynamics, light curves and spectra continue to point to the difficult conclusion that SN~Ia result from degenerate ignition in a carbon/oxygen white dwarf of the Chandrasekhar mass. Such a model accounts well for the ``normal" SN~Ia and for the observed dispersion exemplified by the light curve amplitudeshape relation. The criterion that the white dwarfs involved in this process grow to nearly 1.4 Msun continues to provide a great challenge to understanding the binary stellar evolution involved. The socalled ``supersoft Xray sources" may provide an important new population of SN~Ia progenitors. Other techniques are being developed that may constrain the binary evolution.Is Part Of 19951230 Identifier ISSN: Category astrophLicense 
arXivR(b), R(c) and New Physics: An Updated Model Independent Analysis P. Bamert 19951230 We analyze LEP and SLC data from the 1995 Summer Conferences as well as from low energy neutral current experiments for signals of new physics. The reasons for doing this are twofold, first to explain the deviations from the standard model observed in $R_b$ and $R_c$ and second to constrain nonstandard contributions to couplings of the $Z^0$ boson to all fermions and to the oblique parameters. We do so by comparing the data with the Standard Model as well as with a number of test hypotheses concerning the nature of the new physics. These include nonstandard $Zb\bar{b}$, $Zc\bar{c}$ and $Zs\bar{s}$couplings as well as the couplings of the $Z^0$ to fermions of the entire first, second and third generations and universal corrections to all up and downtype quark couplings (as can arise \eg\ in $Z'$ mixing models). We find that nonstandard $Zb\bar{b}$ couplings are both necessary and sufficient to explain the data and in particular the $R_b$ anomaly. It is not possible to explain $R_b$, $R_c$ and a value of the strong coupling constant consistent with low energy determinations invoking only nonstandard $Zb\bar{b}$ and $Zc\bar{c}$couplings. To do so one has to have also new physics contributions to the $Zs\bar{s}$ or universal corrections to all $Zq\bar{q}$ couplings.
Subject Source arXiv URL https://arxiv.org/abs/hepph/9512445view Article Title R(b), R(c) and New Physics: An Updated Model Independent AnalysisAuthors P. BamertAbstract We analyze LEP and SLC data from the 1995 Summer Conferences as well as from low energy neutral current experiments for signals of new physics. The reasons for doing this are twofold, first to explain the deviations from the standard model observed in $R_b$ and $R_c$ and second to constrain nonstandard contributions to couplings of the $Z^0$ boson to all fermions and to the oblique parameters. We do so by comparing the data with the Standard Model as well as with a number of test hypotheses concerning the nature of the new physics. These include nonstandard $Zb\bar{b}$, $Zc\bar{c}$ and $Zs\bar{s}$couplings as well as the couplings of the $Z^0$ to fermions of the entire first, second and third generations and universal corrections to all up and downtype quark couplings (as can arise \eg\ in $Z'$ mixing models). We find that nonstandard $Zb\bar{b}$ couplings are both necessary and sufficient to explain the data and in particular the $R_b$ anomaly. It is not possible to explain $R_b$, $R_c$ and a value of the strong coupling constant consistent with low energy determinations invoking only nonstandard $Zb\bar{b}$ and $Zc\bar{c}$couplings. To do so one has to have also new physics contributions to the $Zs\bar{s}$ or universal corrections to all $Zq\bar{q}$ couplings.Is Part Of Int.J.Mod.Phys.A12:723742,1997 19951230 Identifier ISSN: DOI 10.1142/S0217751X97000591Category hepphLicense 
arXivGinzburgLandau Expansion and the Slope of the Upper Critical Field in Disordered Superconductors with Anisotropic Pairing A. I. Posazhennikova, M. V. Sadovskii 19951230 It is demonstrated that the slope of the upper critical field $dH_{c2}/dT_{T_{c}}$ in superconductors with $d$wave pairing drops rather fast with concentration of normal impurities, while in superconductors with anisotropic $s$wave pairing $dH_{c2}/dT_{T_{c}}$ grows, and in the limit of strong disorder is described by the known dependences of the theory of ``dirty'' superconductors. This allows to use the measurements of $H_{c2}$ in disordered superconductors to discriminate between these different types of pairing in hightemperature and heavyfermion superconductors.
Subject Source arXiv URL https://arxiv.org/abs/condmat/9512178view Article Title GinzburgLandau Expansion and the Slope of the Upper Critical Field in Disordered Superconductors with Anisotropic PairingAuthors A. I. Posazhennikova; M. V. SadovskiiAbstract It is demonstrated that the slope of the upper critical field $dH_{c2}/dT_{T_{c}}$ in superconductors with $d$wave pairing drops rather fast with concentration of normal impurities, while in superconductors with anisotropic $s$wave pairing $dH_{c2}/dT_{T_{c}}$ grows, and in the limit of strong disorder is described by the known dependences of the theory of ``dirty'' superconductors. This allows to use the measurements of $H_{c2}$ in disordered superconductors to discriminate between these different types of pairing in hightemperature and heavyfermion superconductors.Is Part Of JETP.Lett. 63 (1996) 358 19951230 Identifier ISSN: DOI 10.1134/1.567030Category condmat suprconLicense 
arXivGood Quantum ErrorCorrecting Codes Exist A. R. Calderbank, Peter W. Shor 19951230 A quantum errorcorrecting code is defined to be a unitary mapping (encoding) of k qubits (2state quantum systems) into a subspace of the quantum state space of n qubits such that if any t of the qubits undergo arbitrary decoherence, not necessarily independently, the resulting n qubits can be used to faithfully reconstruct the original quantum state of the k encoded qubits. Quantum errorcorrecting codes are shown to exist with asymptotic rate k/n = 1  2H(2t/n) where H(p) is the binary entropy function p log p  (1p) log (1p). Upper bounds on this asymptotic rate are given.
Subject Source arXiv URL https://arxiv.org/abs/quantph/9512032view Article Title Good Quantum ErrorCorrecting Codes ExistAuthors A. R. Calderbank; Peter W. ShorAbstract A quantum errorcorrecting code is defined to be a unitary mapping (encoding) of k qubits (2state quantum systems) into a subspace of the quantum state space of n qubits such that if any t of the qubits undergo arbitrary decoherence, not necessarily independently, the resulting n qubits can be used to faithfully reconstruct the original quantum state of the k encoded qubits. Quantum errorcorrecting codes are shown to exist with asymptotic rate k/n = 1  2H(2t/n) where H(p) is the binary entropy function p log p  (1p) log (1p). Upper bounds on this asymptotic rate are given.Is Part Of Phys. Rev. A, Vol. 54, No. 2, pp. 10981106, 1996 19951230 Identifier ISSN: DOI 10.1103/PhysRevA.54.1098Category quantphLicense