5,520 research outputs found
A wall-crossing formula for Gromov-Witten invariants under variation of git quotient
We prove a quantum version of Kalkman's wall-crossing formula comparing
Gromov-Witten invariants on geometric invariant theory (git) quotients related
by a change in polarization. The wall-crossing terms are gauged Gromov-Witten
invariants with smaller structure group. As an application, we show that the
graph Gromov-Witten potentials of quotients related by wall-crossings of
crepant type are equivalent up to a distribution in the quantum parameter that
is almost everywhere zero. This is a version of the crepant transformation
conjecture of Li-Ruan, Bryan-Graber, Coates-Ruan etc. in cases where the
crepant transformation is obtained by variation of git.Comment: 64 pages, 1 figure. Expanded and clarified exposition in a number of
places in response to referee comment
IMPACT OF THE DRAWBACK MECHANISMS IN THE CHILEAN SALMON INDUSTRY
Resource /Energy Economics and Policy,
Policy Reforms and Institutional Weaknesses - Closing the Gap
Philipines, development, institutions
An equation of state for purely kinetic k-essence inspired by cosmic topological defects
We investigate the physical properties of a purely kinetic k-essence model
with an equation of state motivated in superconducting membranes. We compute
the equation of state parameter and discuss its physical evolution via a
nonlinear equation of state. Using the adiabatic speed of sound and energy
density, we restrict the range of parameters of the model in order to have an
acceptable physical behavior. Furthermore, we analyze the evolution of the
luminosity distance with redshift by comparing (normalizing) it
with the CDM model. Since the equation of state parameter is
-dependent the evolution of the luminosity distance is also analyzed using
the Alcock-Paczy\'{n}ski test.Comment: 19 pages, 13 figures, typos corrected and references adde
Governance in Southeast Asia: Issues and Options
This paper attempts to analyze governance systems in Southeast Asia and proposes some policy suggestions that can improve governance practices in the region. It also discusses the links between governance and official development assistance (ODA) and the role of the Japan Bank for International Cooperation. To put the discussion on governance systems in a proper context, the paper discusses the governance and growth nexus in Southeast Asia; describes the operating governance systems in Southeast Asia; analyzes economic governance, more specifically in the areas of economic management and growth, revenue generation, social spending, access to services, cost of doing business, and corporate governance; and examines political governance, focusing on the rule of law and judicial independence, conflict management, and voice participation.governance, development program, corruption
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