TY - BOOK A1 - Davis, Simon T1 - The quantum cosmological wavefunction at very early times for a quadratic gravity theory T3 - Preprint / Universität Potsdam, Institut für Mathematik, Arbeitsgruppe Partiell Y1 - 2003 SN - 1437-739X PB - Univ. CY - Potsdam ER - TY - INPR A1 - Davis, Simon T1 - On the absence of large-order divergences in superstring theory N2 - The genus-dependence of multi-loop superstring ams is estimated at large orders in perturbation theory using the super-Schottky group parameterization of supermoduli space. Restriction of the integration region to a subset of supermoduli space and a single fundamental domain of the super-modular group suggests an exponential dependence on the genus. Upper bounds for these estimates are obtained for arbitrary N-point superstring scattering amplitudes and are shown to be consistent with exact results obtained for special type II string amplitudes for orbifold or Calabi-Yau compactifications. The genus-dependence is then obtained by considering the effect of the remaining contribution to the superstring amplitudes after the coefficients of the formally divergent parts of the integrals vanish as a result of a sum over spin structures. The introduction of supersymmetry therefore leads to the elimination of large-order divergences in string pertubation theory, a result which is based only on the supersymmetric generalization of the polyakov measure and not the gauge group of the string model. T3 - Preprint - (2002) 28 Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-26452 ER - TY - JOUR A1 - Seroussi, Helene A1 - Nowicki, Sophie A1 - Payne, Antony J. A1 - Goelzer, Heiko A1 - Lipscomb, William H. A1 - Abe-Ouchi, Ayako A1 - Agosta, Cecile A1 - Albrecht, Torsten A1 - Asay-Davis, Xylar A1 - Barthel, Alice A1 - Calov, Reinhard A1 - Cullather, Richard A1 - Dumas, Christophe A1 - Galton-Fenzi, Benjamin K. A1 - Gladstone, Rupert A1 - Golledge, Nicholas R. A1 - Gregory, Jonathan M. A1 - Greve, Ralf A1 - Hattermann, Tore A1 - Hoffman, Matthew J. A1 - Humbert, Angelika A1 - Huybrechts, Philippe A1 - Jourdain, Nicolas C. A1 - Kleiner, Thomas A1 - Larour, Eric A1 - Leguy, Gunter R. A1 - Lowry, Daniel P. A1 - Little, Chistopher M. A1 - Morlighem, Mathieu A1 - Pattyn, Frank A1 - Pelle, Tyler A1 - Price, Stephen F. A1 - Quiquet, Aurelien A1 - Reese, Ronja A1 - Schlegel, Nicole-Jeanne A1 - Shepherd, Andrew A1 - Simon, Erika A1 - Smith, Robin S. A1 - Straneo, Fiammetta A1 - Sun, Sainan A1 - Trusel, Luke D. A1 - Van Breedam, Jonas A1 - van de Wal, Roderik S. W. A1 - Winkelmann, Ricarda A1 - Zhao, Chen A1 - Zhang, Tong A1 - Zwinger, Thomas T1 - ISMIP6 Antarctica BT - a multi-model ensemble of the Antarctic ice sheet evolution over the 21st century JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union N2 - Ice flow models of the Antarctic ice sheet are commonly used to simulate its future evolution in response to different climate scenarios and assess the mass loss that would contribute to future sea level rise. However, there is currently no consensus on estimates of the future mass balance of the ice sheet, primarily because of differences in the representation of physical processes, forcings employed and initial states of ice sheet models. This study presents results from ice flow model simulations from 13 international groups focusing on the evolution of the Antarctic ice sheet during the period 2015-2100 as part of the Ice Sheet Model Intercomparison for CMIP6 (ISMIP6). They are forced with outputs from a subset of models from the Coupled Model Intercomparison Project Phase 5 (CMIP5), representative of the spread in climate model results. Simulations of the Antarctic ice sheet contribution to sea level rise in response to increased warming during this period varies between 7:8 and 30.0 cm of sea level equivalent (SLE) under Representative Concentration Pathway (RCP) 8.5 scenario forcing. These numbers are relative to a control experiment with constant climate conditions and should therefore be added to the mass loss contribution under climate conditions similar to present-day conditions over the same period. The simulated evolution of the West Antarctic ice sheet varies widely among models, with an overall mass loss, up to 18.0 cm SLE, in response to changes in oceanic conditions. East Antarctica mass change varies between 6 :1 and 8.3 cm SLE in the simulations, with a significant increase in surface mass balance outweighing the increased ice discharge under most RCP 8.5 scenario forcings. The inclusion of ice shelf collapse, here assumed to be caused by large amounts of liquid water ponding at the surface of ice shelves, yields an additional simulated mass loss of 28mm compared to simulations without ice shelf collapse. The largest sources of uncertainty come from the climate forcing, the ocean-induced melt rates, the calibration of these melt rates based on oceanic conditions taken outside of ice shelf cavities and the ice sheet dynamic response to these oceanic changes. Results under RCP 2.6 scenario based on two CMIP5 climate models show an additional mass loss of 0 and 3 cm of SLE on average compared to simulations done under present-day conditions for the two CMIP5 forcings used and display limited mass gain in East Antarctica. Y1 - 2020 U6 - https://doi.org/10.5194/tc-14-3033-2020 SN - 1994-0416 SN - 1994-0424 VL - 14 IS - 9 SP - 3033 EP - 3070 PB - Copernicus CY - Göttingen ER - TY - BOOK A1 - Davis, Simon T1 - Connections and generalized gauge transformation T3 - Preprint / Universität Potsdam, Institut für Mathematik, Arbeitsgruppe Partiell Y1 - 2002 SN - 1437-739X PB - Univ. CY - Potsdam ER - TY - BOOK A1 - Davis, Simon T1 - On the absence of large-order divergences in superstring theory T3 - Preprint / Universität Potsdam, Institut für Mathematik, Arbeitsgruppe Partiell Y1 - 2002 SN - 1437-739X PB - Univ. CY - Potsdam ER - TY - BOOK A1 - Davis, Simon T1 - On the existence of a non-zero lower bound for the number of goldbach partitions of an even integer T3 - Preprint / Universität Potsdam, Institut für Mathematik, Arbeitsgruppe Partiell Y1 - 2002 SN - 1437-739X PB - Univ. CY - Potsdam ER - TY - INPR A1 - Davis, Simon T1 - Connections and generalized gauge transformations N2 - The derivation of the standard model from a higher-dimensional action suggests a further study of the fibre bundle formulation of gauge theories to determine the variations in the choice of structure group that are allowed in this geometrical setting. The action of transformations on the projection of fibres to their submanifolds are characteristic of theories with fewer gauge vector bosons, and specific examples are given, which may have phenomenological relevance. The spinor space for the three generations of fermions in the standard model is described algebraically. T3 - Preprint - (2002) 29 KW - bundles KW - connections KW - fibre coordinates KW - parallelizable spheres KW - division algebras KW - force unification Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-26468 ER - TY - INPR A1 - Davis, Simon T1 - On the existence of a non-zero lower bound for the number of Goldbach partitions of an even integer N2 - The Goldbach partitions of an even number greater than 2, given by the sums of two prime addends, form the non-empty set for all integers 2n with 2 ≤ n ≤ 2 × 1014. It will be shown how to determine by the method of induction the existence of a non-zero lower bound for the number of Goldbach partitions of all even integers greater than or equal to 4. The proof depends on contour arguments for complex functions in the unit disk. T3 - Preprint - (2002) 30 Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-26474 ER - TY - INPR A1 - Davis, Simon T1 - The quantum cosmological wavefunction at very early times for a quadratic gravity theory N2 - The quantum cosmological wavefunction for a quadratic gravity theory derived from the heterotic string effective action is obtained near the inflationary epoch and during the initial Planck era. Neglecting derivatives with respect to the scalar field, the wavefunction would satisfy a third-order differential equation near the inflationary epoch which has a solution that is singular in the scale factor limit a(t) → 0. When scalar field derivatives are included, a sixth-order differential equation is obtained for the wavefunction and the solution by Mellin transform is regular in the a → 0 limit. It follows that inclusion of the scalar field in the quadratic gravity action is necessary for consistency of the quantum cosmology of the theory at very early times. T3 - Preprint - (2003) 04 Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-26520 ER -