15,683 research outputs found

    Dispersion managed mode-locking dynamics in a Ti:Sapphire laser

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    We present what is to our knowledge the most complete 1-D numerical analysis of the evolution and the propagation dynamics of an ultrashort laser pulse in a Ti:Sapphire laser oscillator. This study confirms the dispersion managed model of mode-locking, and emphasizes the role of the Kerr nonlinearity in generating mode-locked spectra with a smooth and well-behaved spectral phase. A very good agreement with preliminary experimental measurements is found.Comment: 11 pages, 4 figures, submitted to Optics Letter

    Harnack's Inequality for Parabolic De Giorgi Classes in Metric Spaces

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    In this paper we study problems related to parabolic partial differential equations in metric measure spaces equipped with a doubling measure and supporting a Poincare' inequality. We give a definition of parabolic De Giorgi classes and compare this notion with that of parabolic quasiminimizers. The main result, after proving the local boundedness, is a scale and location invariant Harnack inequality for functions belonging to parabolic De Giorgi classes. In particular, the results hold true for parabolic quasiminimizers

    Sistem Pendukung Keputusan Pemilihan Pts Di Lhokseumawe Menggunakan Metode Fuzzy Ahp Berbasis Web

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    Sistem Pendukung Keputusan pemilihan PTS ini bertujuan untuk memberikan dukungan pengambilan keputusan untuk pemilihan sebuah PTS di Lhokseumawe. Pada sistem ini terdapat 11 alternatif perguruan tinggi swasta dan ada 6 kriteria yang digunakan oleh sistem. Sistem ini menggunakan metode fuzzy untuk kriteriayang bobot nilainya tidak tetap, kriteria tersebut diantaranya jumlah lulusan, Jarak dengan kota, Biaya pendidikan, jumlah dosen dan pendidikan dosen serta menggunakan metode Analytic Hierarchy Process (AHP) yaitu untuk perangkingan Perguruan Tinggi yang dipilih oleh user. Pemberian nilai fuzzy berlaku untuk setiap kriteria yang ada. Pada sistem ini juga terdapat 2 proses yakni proses pemilihan perguruan tinggi swasta dan proses membandingkan tingkat kepentingan antar kriteria. Perhitungan fuzzy pada sistem ini tidak dilakukan di dalam sistem melainkan di input oleh admin sistem yang telah dicari terlebih dahulu nilai fuzzy kriteria untuk tiap alternatif yang ada. Hasil dari proses fuzzy dan AHP dalam aplikasi ini akan menghasilkan perangkingan untuk alternatif yang dipilih oleh user

    Valence-bond theory of highly disordered quantum antiferromagnets

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    We present a large-N variational approach to describe the magnetism of insulating doped semiconductors based on a disorder-generalization of the resonating-valence-bond theory for quantum antiferromagnets. This method captures all the qualitative and even quantitative predictions of the strong-disorder renormalization group approach over the entire experimentally relevant temperature range. Finally, by mapping the problem on a hard-sphere fluid, we could provide an essentially exact analytic solution without any adjustable parameters.Comment: 5 pages, 3 eps figure

    Performing the Network

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    SĂ©ance: a networked glossalalia is a networked performance that is part of the media art project, The Perpetual Emotion Project. Both are animated by our interest in the non-instrumental and the non-sensical and in the making of performative events. In this paper we present the work as practice-led research, which contributes to the understanding and development of what we identify as performative media art. This paper is an expanded version of a paper presented at E-Performance and Plug-ins, UNSW, 2006

    3d Modularity

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    We find and propose an explanation for a large variety of modularity-related symmetries in problems of 3-manifold topology and physics of 3d N=2\mathcal{N}=2 theories where such structures a priori are not manifest. These modular structures include: mock modular forms, SL(2,Z)SL(2,\mathbb{Z}) Weil representations, quantum modular forms, non-semisimple modular tensor categories, and chiral algebras of logarithmic CFTs.Comment: 119 pages, 10 figures and 20 table

    Elliptic Genera and 3d Gravity

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    We describe general constraints on the elliptic genus of a 2d supersymmetric conformal field theory which has a gravity dual with large radius in Planck units. We give examples of theories which do and do not satisfy the bounds we derive, by describing the elliptic genera of symmetric product orbifolds of K3K3, product manifolds, certain simple families of Calabi-Yau hypersurfaces, and symmetric products of the "Monster CFT." We discuss the distinction between theories with supergravity duals and those whose duals have strings at the scale set by the AdS curvature. Under natural assumptions we attempt to quantify the fraction of (2,2) supersymmetric conformal theories which admit a weakly curved gravity description, at large central charge.Comment: 50 pages, 9 figures, v2: minor corrections to section
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