637 research outputs found
Expanded degenerations and pairs
No full textWe provide a universal approach to the moduli of Jun Li's expanded pairs and expanded degenerations. This enables us to prove algebraicity results, compare with Li's approach and with the approach of Graber and Vakil, and generalize to the twisted expansions used by Abramovich and Fantechi as a basis for orbifold techniques in degeneration formulas
Tame stacks in positive characteristic
No full textWe introduce and study a class of algebraic stacks with finite inertia in positive and mixed characteristic, which we call tame algebraic stacks. They include tame Deligne-Mumford stacks, and are arguably better behaved than general Deligne-Mumford stacks. We also give a complete characterization of finite flat linearly reductive schemes over an arbitrary base. Our main result is that tame algebraic stacks are etale locally quotient by actions of linearly reductive finite group schemes
Gromov-Witten theory of Deligne-Mumford stacks
No full textGiven a smooth complex Deligne-Mumford stack X with a projective coarse moduli space. we introduce Gromov-Witten invariants of X and prove some of their basic properties, including the WDVV equation
Pulse Buckling of a Thin-Walled CFRP Cylindrical Shell – A Numerical Approach
No full textThe present study investigates the behaviour of a CFRP cylindrical shell under compressive pulse loading. The in-pulse analyses are performed numerically, using the finite element code ABAQUS. The dynamic buckling load is determined using the Budiansky & Hutchinson criterion. Parameters like the shape of pulse loading and pulse duration were varied, and their influence on the Dynamic Load Factor (DLF) was investigated. The investigation shows that DLF tends to increase well above unity for short duration impulses, while for the larger duration the value is decreasing towards unity. The shape of the pulse also has a significant influence on the DLF value. DLF<1 was found only for a trapezoidal pulse. For sinusoidal pulse shape, the static buckling load of the CFRP shell was consistently below the dynamic one.Aerospace Structures & Computational Mechanic
A Touch of Genius: Portraits and Literary Masterpieces
No full textIn a collection of passionate, sparkling essays, one of Australia’s leading literary critics presents a fresh and exciting ode to Jewish fiction. Rescuing some brilliant texts from the dustbin of oblivion or from culture’s short-memory, Abramovich, writing with affection and authority, offers gems of critical appreciation and in-depth discussion of masterpieces and iconic authors such as Nobel Prize Winner S.Y. Agnon, Israel’s most celebrated living author Amos Oz, the mesmerising Paul Celan, the incomparable David Grossman, the extraordinary Susan Fromberg Schaeffer, the Israeli ‘Agatha Christie’, and the early pioneers of Hebrew letters. Sharing his lifetime joy of reading and engagement with the written word, and showcasing his scholarly erudition, Abramovich effortlessly muses on the nature of writing, and takes readers on an intellectual and philosophical journey through grand thematic landscapes such as memory, the Holocaust, identity, man’s relationship with God, imagination, family, marriage death and suffering. A celebration and a tribute to old favourites, this delightful volume of reflections and meditations is sure to ignite a fire in the discerning readers’ minds, and motivate them to go back to those classics with a renewed sense of excitement. Certain to become a valuable and entertaining guide for anyone who loves Israeli and Jewish fiction, this work will provide inspiration and reason aplenty to turn off the computer or TV and start reading again
The tropicalization of the moduli space of curves.
No full textWe show that the skeleton of the Deligne-Mumford-Knudsen
moduli stack of stable curves is naturally identified with the moduli
space of extended tropical curves, and that this is compatible with the ``naive" set-theoretic tropicalization map. The proof passes through general structure results on the skeleton of a toroidal Deligne-Mumford stack. Furthermore, we construct tautological forgetful, clutching, and gluing maps between moduli spaces of extended tropical curves and show that they are compatible with the analogous tautological maps in the algebraic setting.On d'{e}montre que la squelette du champ des modules des courbes stables de Deligne-Mumford-Knudsen
est naturellement identifi'{e} avec l'espace des modules des courbes tropicales de fac{c}on compatible avec l'application de tropicalisation ``na"ive" d'ensembles. La d'{e}monstration emploi des r'{e}sultats g'{e}n'{e}raux de structure sur la squelette des champs toro"{i}daux de Deligne-Mum-ford. En outre, on construit les morphismes tautologiques entre les espaces de modules des courbes tropicales '{e}tendues, et l'on d'{e}montre qu'ils sont compatibles avec leurs analogues dans le cadre alg'{e}brique
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