355 research outputs found
Genus four superstring measures
A main issue in superstring theory are the superstring measures. D'Hoker and
Phong showed that for genus two these reduce to measures on the moduli space of
curves which are determined by modular forms of weight eight and the bosonic
measure. They also suggested a generalisation to higher genus. We showed that
their approach works, with a minor modification, in genus three and we
announced a positive result also in genus four. Here we give the modular form
in genus four explicitly. Recently S. Grushevsky published this result as part
of a more general approach.Comment: 7 pages. To appear in Letters in Mathematical Physic
Recommended from our members
Memory objects in project environments: Storing, retrieving and adapting learning in project-based firms
This paper investigates the role of objects holding representations of knowledge in the transfer of learning across projects. On the basis of an in-depth case study, this paper shows that the way in which relatively simple artifacts, such as Excel workbooks, represent knowledge enables them to act as boundary objects across occupations and as memory devices across projects. It is the temporal capacity of these boundary objects that makes them points of juncture in a widely distributed memory system, enabling project-based firms to balance preservation and adaptation of knowledge. The mechanisms for the preservation of learning are not missing from project environments, rather they are less visible and less direct than in other settings, and therefore less docile in the face of managerial action
Classical theta constants vs. lattice theta series, and super string partition functions
Recently, various possible expressions for the vacuum-to-vacuum superstring
amplitudes has been proposed at genus . To compare the different
proposals, here we will present a careful analysis of the comparison between
the two main technical tools adopted to realize the proposals: the classical
theta constants and the lattice theta series. We compute the relevant Fourier
coefficients in order to relate the two spaces. We will prove the equivalence
up to genus 4. In genus five we will show that the solutions are equivalent
modulo the Schottky form and coincide if we impose the vanishing of the
cosmological constant.Comment: 21 page
Recommended from our members
The long and winding road: Routine creation and replication in multi-site organizations
Prior research on organizational routines in the ‘capabilities’ literature has either studied how new routines are created during an exploratory process of variation and selection or how existing routines are replicated during a phase of exploitation. Few studies have analyzed the life cycle of new routine creation and replication as an integrated process. In an in-depth case study of England’s Highways Agency, this paper shows that the creation and replication of a new routine across multiple sites involves four sequential steps: envisioning, experimenting, entrenching and enacting. We contribute to the capabilities research in two ways: first, by showing how different organizational levels, capabilities and logics (cognitive and behavioural) shape the development of new routines; and second, by identifying how distinct evolutionary cycles of variation and selective retention occur during each step in the process. In contrast with prior research on replication as an exact copy of a template or existing routine, our study focuses on the replication of an entirely new routine (based on novel principles) that is adapted to fit local operational conditions during its large-scale replication across multiple sites. We draw upon insights from adjacent ‘practice research’ and suggest how capabilities and practice studies may complement each other in future research on the evolution of routines
Eluding SUSY at every genus on stable closed string vacua
In closed string vacua, ergodicity of unipotent flows provide a key for
relating vacuum stability to the UV behavior of spectra and interactions.
Infrared finiteness at all genera in perturbation theory can be rephrased in
terms of cancelations involving only tree-level closed strings scattering
amplitudes. This provides quantitative results on the allowed deviations from
supersymmetry on perturbative stable vacua. From a mathematical perspective,
diagrammatic relations involving closed string amplitudes suggest a relevance
of unipotent flows dynamics for the Schottky problem and for the construction
of the superstring measure.Comment: v2, 17 pages, 8 figures, typos corrected, new figure added with 3
modular images of long horocycles,(obtained with Mathematica
Recommended from our members
The multiplicity of habit: Implications for routines research
This chapter explores habit as a foundational concept for routines research. The authors examine how habit and habitus have been conceptualized in psychology and sociology, giving particular attention to the role of deliberation and mindfulness. Drawing on this work, they develop a typology of habit that is based on the extent of deliberation by the individual performing an activity, and the variability in the conditions in which he or she performs it. The chapter considers the implications of these insights on habit for two central perspectives of organizational routines, the capabilities perspective and the practice perspective, arguing that both can be advanced by closer attention to the idea of routines as interlinked habits
Equidistribution Rates, Closed String Amplitudes, and the Riemann Hypothesis
We study asymptotic relations connecting unipotent averages of
automorphic forms to their integrals over the moduli space
of principally polarized abelian varieties. We obtain reformulations of the
Riemann hypothesis as a class of problems concerning the computation of the
equidistribution convergence rate in those asymptotic relations. We discuss
applications of our results to closed string amplitudes. Remarkably, the
Riemann hypothesis can be rephrased in terms of ultraviolet relations occurring
in perturbative closed string theory.Comment: 15 page
Recommended from our members
Project-based Temporary Organizing and Routine Dynamics
Projects are forms of organizing that have become increasingly common in the past decades. The ad-hoc and temporary nature of projects seemingly poses significant challenges to the patterning of activities into organizational routines. Yet, considerable research in routine dynamics has been carried out in project contexts. In this chapter, we show that projects and routines share some common characteristics and that acknowledging the project nature of routines as well as the organizational routine nature of projects offers significant opportunities for the advancement of routine dynamics research
Recommended from our members
Knowledge transfer across projects: Codification in creative, high-tech and engineering industries
The use of codification to support knowledge transfer across projects has been explored in several recent, and mostly qualitative, studies. Building on that research, this article puts forward hypotheses about the antecedents of knowledge codification, and tests them on a sample of 540 inter-organizational projects carried out in the creative, high-tech and engineering industries. We find that the presence of strong industry norms governing the division of labour discourages knowledge transfer through codification, as suggested by the existing qualitative studies. The presence of a system integrator plays an important role in driving the use of codification for knowledge transfer, to some extent embodying an organizational memory in volatile project environments. Finally, the level of use of administrative control in the project is a robust predictor of attempts to transfer knowledge via codification. When these antecedents are taken into account, the novelty of products and services plays a smaller role than previously found in determining the use of codification
The vanishing of two-point functions for three-loop superstring scattering amplitudes
In this paper we show that the two-point function for the three-loop chiral
superstring measure ansatz proposed by Cacciatori, Dalla Piazza, and van Geemen
vanishes. Our proof uses the reformulation of ansatz in terms of even cosets,
theta functions, and specifically the theory of the linear system
on Jacobians introduced by van Geemen and van der Geer.
At the two-loop level, where the amplitudes were computed by D'Hoker and
Phong, we give a new proof of the vanishing of the two-point function (which
was proven by them). We also discuss the possible approaches to proving the
vanishing of the two-point function for the proposed ansatz in higher genera
- …