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78
Distributions of flux vacua
 JHEP
"... Abstract: We give results for the distribution and number of flux vacua of various types, supersymmetric and nonsupersymmetric, in IIb string theory compactified on CalabiYau manifolds. We compare this with related problems such as counting attractor points. Contents ..."
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Cited by 166 (18 self)
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Abstract: We give results for the distribution and number of flux vacua of various types, supersymmetric and nonsupersymmetric, in IIb string theory compactified on CalabiYau manifolds. We compare this with related problems such as counting attractor points. Contents
Building a better racetrack
 JHEP 0406
"... We find IIb compactifications on CalabiYau orientifolds in which all Kähler moduli are stabilized, along lines suggested by Kachru, Kallosh, Linde and Trivedi. ..."
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Cited by 119 (8 self)
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We find IIb compactifications on CalabiYau orientifolds in which all Kähler moduli are stabilized, along lines suggested by Kachru, Kallosh, Linde and Trivedi.
Generic Rules For High Temperature Dimensional Reduction And Their Application To The Standard Model
, 1995
"... We formulate the rules for dimensional reduction of a generic finite temperature gauge theory to a simpler threedimensional effective bosonic theory in terms of a matching of Green's functions in the full and the effective theory, and present a computation of a generic set of 1 and 2loop gra ..."
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Cited by 38 (7 self)
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We formulate the rules for dimensional reduction of a generic finite temperature gauge theory to a simpler threedimensional effective bosonic theory in terms of a matching of Green's functions in the full and the effective theory, and present a computation of a generic set of 1 and 2loop graphs needed for the application of these rules. As a concrete application we determine the explicit mapping of the physical parameters of the standard electroweak theory to a threedimensional SU(2)\ThetaU(1) gaugeHiggs theory. We argue that this threedimensional theory has a universal character and appears as an effective theory for many extensions of the Standard Model. 1 kajantie@phcu.helsinki.fi 2 mlaine@phcu.helsinki.fi 3 kari@trek.physics.indiana.edu 4 mshaposh@nxth04.cern.ch 1 Introduction The properties of matter at high temperature are interesting for a number of experimental and cosmological applications. QCD at high temperature and density may be relevant for heavy ion colli...
Taylor models and other validated functional inclusion methods
 Int. J. Pure Appl. Math
"... Abstract: A detailed comparison between Taylor model methods and other tools for validated computations is provided. Basic elements of the Taylor model (TM) methods are reviewed, beginning with the arithmetic for elementary operations and intrinsic functions. We discuss some of the fundamental prope ..."
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Cited by 37 (3 self)
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Abstract: A detailed comparison between Taylor model methods and other tools for validated computations is provided. Basic elements of the Taylor model (TM) methods are reviewed, beginning with the arithmetic for elementary operations and intrinsic functions. We discuss some of the fundamental properties, including high approximation order and the ability to control the dependency problem, and pointers to many of the more advanced TM tools are provided. Aspects of the current implementation, and in particular the issue of floating point error control, are discussed. For the purpose of providing range enclosures, we compare with modern versions of centered forms and mean value forms, as well as the direct computation of remainder bounds by highorder interval automatic differentiation and show the advantages of the TM methods. We also compare with the socalled boundary arithmetic (BA) of Lanford, Eckmann, Wittwer, Koch et al., which was developed to prove existence of fixed points in several comparatively small systems, and the ultraarithmetic (UA) developed by Kaucher, Miranker et al. which
Inflationary Constraints on Type IIA String Theory
 Rev. D
"... We prove that inflation is forbidden in the most well understood class of semirealistic type IIA string compactifications: CalabiYau compactifications with only standard NSNS 3form flux, RR fluxes, D6branes and O6planes at large volume and small string coupling. With these ingredients, the fi ..."
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Cited by 18 (1 self)
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We prove that inflation is forbidden in the most well understood class of semirealistic type IIA string compactifications: CalabiYau compactifications with only standard NSNS 3form flux, RR fluxes, D6branes and O6planes at large volume and small string coupling. With these ingredients, the first slowroll parameter satisfies ǫ ≥ 27 13 whenever V> 0, ruling out both inflation (including brane/antibrane inflation) and de Sitter vacua in this limit. Our proof is based on the dependence of the 4dimensional potential on the volume and dilaton moduli in the presence of fluxes and branes. We also describe broader classes of IIA models which may include cosmologies with inflation and de Sitter vacua. The inclusion of extra ingredients, such as NS 5branes and geometric or nongeometric NSNS fluxes, evades the assumptions used in deriving the nogo theorem. We focus on NS 5branes and outline how such ingredients may prove fruitful for cosmology, but we do not provide an explicit model. We contrast the results of our IIA analysis with the rather different situation in IIB. Electronic address: mphertz at mit.edu
Effective Tachyonic Potential in Closed String Field Theory
 Nucl. Phys. B
, 1995
"... We calculate the effective tachyonic potential in closed string field theory up to the quartic term in the tree approximation. This involves an elementary fourtachyon vertex and a sum over the infinite number of Feynman graphs with an intermediate massive state. We show that both the elementary ter ..."
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Cited by 17 (0 self)
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We calculate the effective tachyonic potential in closed string field theory up to the quartic term in the tree approximation. This involves an elementary fourtachyon vertex and a sum over the infinite number of Feynman graphs with an intermediate massive state. We show that both the elementary term and the sum can be evaluated as integrals of some measure over different regions in the moduli space of fourpunctured spheres. We show that both elementary and effective coupling give negative contributions to the quartic term in the tachyon potential. Numerical calculations show that the fourth order term is big enough to destroy a local minimum which exists in the third order approximation.
Machine Tongues XV: Three Packages for Software Sound Synthesis
 Computer Music Journal
"... This article will discuss the technology of SWSS and then present and compare these three systems. It is divided into three parts; the first introduces SWSS in terms of progressive examples. Part two compares the three systems using the same two instrument/score examples written in each of them. The ..."
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Cited by 17 (5 self)
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This article will discuss the technology of SWSS and then present and compare these three systems. It is divided into three parts; the first introduces SWSS in terms of progressive examples. Part two compares the three systems using the same two instrument/score examples written in each of them. The final section presents informal benchmark tests of the systems run on two different hardware platformsa Sun Microsystems SPARCstation2 IPX and a Next Computer Inc. TurboCube machineand subjective comments on various features of the languages and programming environments of stateoftheart SWSS software. This author's connection with this topic is that of extensive experience with several different SWSS systems over the last 15 years, starting with MUS10 and including all three compared here: Csound (in the form of Music11 initially) at the CMRS studio in Salzburg (Pope 1982); cmusic in the CARL environment at PCS/Cadmus computers in Munich (Pope 1986); and more recently a combination of cmix, Csound, and various vocoder software packages with user interfaces written in Smalltalk80 at the CCRMA Center for Computer Research in Music and Acoustics at Stanford University (Pope 1992).
The Limits to Communitybased Environmental Planning: Operational Dilemmas and Practical Remedies
 Journal of Environmental Planning and Management
, 2005
"... ABSTRACT The operational dilemmas and challenges associated with the practice of communitybased environmental planning (CBEP) are examined. The paper examines the frequently invoked ‘bottomup ’ versus ‘topdown ’ dichotomy and argues that environmental governance is more complex, dynamic and multi ..."
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Cited by 16 (2 self)
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ABSTRACT The operational dilemmas and challenges associated with the practice of communitybased environmental planning (CBEP) are examined. The paper examines the frequently invoked ‘bottomup ’ versus ‘topdown ’ dichotomy and argues that environmental governance is more complex, dynamic and multiscalar than this simple dichotomy implies. The paper identifies six key problems with the CBEP approach: (i) the conceptualization of ‘community ’ which poorly accounts for difference; (ii) problems of inequality; (iii) the organizational capacity and efficacy of community groups; (iv) the scale of CBEP; (v) the types of knowledge utilized by communities in environmental management; and (vi) the potential for parochial concerns to dominate the priorities and agenda of community organizations. The paper analyses each of these issues, identifies planning principles that may aid resolution, and suggests possible remedies.
Scheduling Tertiary I/O in Database Applications
 IN PROC. OF THE 8TH INTERNATIONAL WORKSHOP ON DATABASE AND EXPERT SYSTEMS APPLICATIONS
, 1997
"... We study the problem of scheduling I/O requests for tertiary storage libraries to improve performance. The focus is on scheduling policies that process all requests on a loaded medium before unloading it. For single drive settings an efficient algorithm that produces optimal schedules is developed. ..."
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Cited by 14 (3 self)
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We study the problem of scheduling I/O requests for tertiary storage libraries to improve performance. The focus is on scheduling policies that process all requests on a loaded medium before unloading it. For single drive settings an efficient algorithm that produces optimal schedules is developed. For multiple drives the problem is shown to be NPComplete. Efficient and effective heuristics are presented for the multiple drives case. The scheduling policies developed achieve significant performance gains over more naive first come first server policies. The study is general enough to be applicable to any storage library handling removable media, such as tapes or optical disks.
Parameter estimation for a mathematical model of the cell cycle in frog eggs
 Journal of Computational Biology
, 2005
"... Parameter values for a kinetic model of the nuclear replication–division cycle in frog eggs are estimated by fitting solutions of the kinetic equations (nonlinear ordinary differential equations) to a suite of experimental observations. A set of optimal parameter values is found by minimizing an obj ..."
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Cited by 11 (2 self)
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Parameter values for a kinetic model of the nuclear replication–division cycle in frog eggs are estimated by fitting solutions of the kinetic equations (nonlinear ordinary differential equations) to a suite of experimental observations. A set of optimal parameter values is found by minimizing an objective function defined as the orthogonal distance between the data and the model. The differential equations are solved by LSODAR and the objective function is minimized by ODRPACK. The optimal parameter values are close to the “guesstimates” of the modelers who first studied this problem. These tools are sufficiently general to attack more complicated problems, where guesstimation is impractical or unreliable. Key words: cyclindependent kinase, Mphase promoting factor, orthogonal distance regression, LevenbergMarquardt method. 1.