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Five Dimensional SUSY Field Theories, Nontrivial Fixed Points and String Dynamics
, 1996
"... We study (nonrenormalizable) five dimensional supersymmetric field theories. The theories are parametrized by quark masses and a gauge coupling. We derive the metric on the Coulomb branch exactly. We use stringy considerations to learn about new nontrivial interacting field theories with exception ..."
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Cited by 122 (1 self)
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We study (nonrenormalizable) five dimensional supersymmetric field theories. The theories are parametrized by quark masses and a gauge coupling. We derive the metric on the Coulomb branch exactly. We use stringy considerations to learn about new nontrivial interacting field theories with exceptional global symmetry En (E8, E7, E6, E5 = Spin(10), E4 = SU(5), E3 = SU(3) ×SU(2), E2 = SU(2) ×U(1) and E1 = SU(2)). Their Coulomb branch is R + and their Higgs branch is isomorphic to the moduli space of En instantons. One of the relevant operators of these theories leads to a flow to SU(2) gauge theories with Nf = n − 1 flavors. In terms of these SU(2) IR theories this relevant parameter is the inverse gauge coupling constant. Other relevant operators (which become quark masses after flowing to the SU(2) theories) lead to flows between them. Upon further compactifications to four and three dimensions we find new fixed points with exceptional symmetries.
Extremal Transitions and FiveDimensional supersymmetric field theories
, 1996
"... We study fivedimensional supersymmetric field theories with onedimensional Coulomb branch. We extend a previous analysis which led to nontrivial fixed points with En symmetry (E8, E7, E6, E5 = Spin(10), E4 = SU(5), E3 = SU(3) × SU(2), E2 = SU(2) × U(1) and E1 = SU(2)) by finding two new theories ..."
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Cited by 113 (11 self)
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We study fivedimensional supersymmetric field theories with onedimensional Coulomb branch. We extend a previous analysis which led to nontrivial fixed points with En symmetry (E8, E7, E6, E5 = Spin(10), E4 = SU(5), E3 = SU(3) × SU(2), E2 = SU(2) × U(1) and E1 = SU(2)) by finding two new theories: ˜ E1 with U(1) symmetry and E0 with no symmetry. The latter is a nontrivial theory with no relevant operators preserving the superPoincaré symmetry. In terms of string theory these new field theories enable us to describe compactifications of the type I ′ theory on S 1 /Z2 with 16, 17 or 18 background D8branes. These theories also play a crucial role in compactifications of Mtheory on Calabi– Yau spaces, providing physical models for the contractions of del Pezzo surfaces to points (thereby completing the classification of singularities which can occur at codimension one in Kähler moduli). The structure of the Higgs branch yields a prediction which unifies the known mathematical facts about del Pezzo transitions in a quite remarkable way.
Out of this world supersymmetry breaking
 Nucl. Phys. B
, 1999
"... We show that in a general hidden sector model, supersymmetry breaking necessarily generates at oneloop a scalar and gaugino mass as a consequence of the superWeyl anomaly. We study a scenario in which this contribution dominates. We consider the Standard Model particles to be localized on a (3+1) ..."
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Cited by 68 (1 self)
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We show that in a general hidden sector model, supersymmetry breaking necessarily generates at oneloop a scalar and gaugino mass as a consequence of the superWeyl anomaly. We study a scenario in which this contribution dominates. We consider the Standard Model particles to be localized on a (3+1)dimensional subspace or “3brane ” of a higher dimensional spacetime, while supersymmetry breaking occurs off the 3brane, either in the bulk or on another 3brane. At least one extra dimension is assumed to be compactified roughly one to two orders of magnitude below the fourdimensional Planck scale. This framework is phenomenologically very attractive; it introduces new possibilities for solving the supersymmetric flavor problem, the gaugino mass problem, the supersymmetric CP problem, and the µproblem. Furthermore, the compactification scale can be consistent with a unification of gauge and gravitational couplings. We demonstrate these claims in a fourdimensional effective theory below the compactification scale that incorporates the relevant features of the underlying higher dimensional theory and the contribution of the superWeyl anomaly. Naturalness constraints follow not only from symmetries but also from the higher dimensional
Stable 85Rb BoseEinstein condensates with widely tunable interactions, Phys
 Rev. Lett
"... BoseEinstein condensation has been achieved in a magnetically trapped sample of 85 Rb atoms. Longlived condensates of up to 10 4 atoms have been produced by using a magneticfieldinduced Feshbach resonance to reverse the sign of the scattering length. This system provides many unique opportunitie ..."
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Cited by 38 (0 self)
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BoseEinstein condensation has been achieved in a magnetically trapped sample of 85 Rb atoms. Longlived condensates of up to 10 4 atoms have been produced by using a magneticfieldinduced Feshbach resonance to reverse the sign of the scattering length. This system provides many unique opportunities for the study of condensate physics. The variation of the scattering length near the resonance has been used to magnetically tune the condensate selfinteraction energy over a very wide range. This range extended from very strong repulsive to large attractive selfinteractions. When the interactions were switched from repulsive to attractive, the condensate shrank to below our resolution limit, and after ∼5ms emitted a burst of highenergy atoms. 1 Typeset using REVTEXAtomatom interactions have a profound influence on most of the properties of BoseEinstein condensation (BEC) in dilute alkali gases. These interactions are well described in a meanfield model by a selfinteraction energy that depends only on the density of
Euglossine bees as longdistance pollinators of tropical plants
 Science
, 1971
"... you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, noncommercial use. Please contact the publisher regarding any further use of this work. Publisher contact inform ..."
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Cited by 31 (0 self)
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you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, noncommercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at
Shape Invariant Potentials in “Discrete Quantum Mechanics”
, 2004
"... Shape invariance is an important ingredient of many exactly solvable quantum mechanics. Several examples of shape invariant “discrete quantum mechanical systems” are introduced and discussed in some detail. They arise in the problem of describing the equilibrium positions of RuijsenaarsSchneider ty ..."
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Cited by 26 (14 self)
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Shape invariance is an important ingredient of many exactly solvable quantum mechanics. Several examples of shape invariant “discrete quantum mechanical systems” are introduced and discussed in some detail. They arise in the problem of describing the equilibrium positions of RuijsenaarsSchneider type systems, which are “discrete” counterparts of Calogero and Sutherland systems, the celebrated exactly solvable multiparticle dynamics. Deformed Hermite and Laguerre polynomials are the typical examples of the eigenfunctions of the above shape invariant discrete quantum mechanical systems.
Nontrivial fixed points of the renormalization group in six dimensions
, 1997
"... We start a systematic analysis of supersymmetric field theories in six dimensions. We find necessary conditions for the existence of nontrivial interacting fixed points. String theory provides us with examples of such theories. We conjecture that there are many other examples. September 1996Recent ..."
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Cited by 23 (0 self)
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We start a systematic analysis of supersymmetric field theories in six dimensions. We find necessary conditions for the existence of nontrivial interacting fixed points. String theory provides us with examples of such theories. We conjecture that there are many other examples. September 1996Recent developments in quantum field theory have led to the discovery of a large number of nontrivial interacting fixed points of the renormalization group. Some of these theories were discovered using recent advances in string duality [18]. On the moduli space of vacua of some these theories there are string like excitations. Their tension approaches zero at singular points in the moduli space. Therefore, these theories are often referred to as “tensionless string theories. ” It is our view that they are conventional interacting local quantum field theories. This possible interpretation was first mentioned in [1,4] but became more clear after one of these theories (in three dimensions) was given a Lagrangian description [9] and the renormalization group flows out of the five dimensional theories appeared consistent with field theory [7]. It is likely that some of these theories do not arise under renormalization group flow
Formation, stability, and breakup of nanojets
 Science
"... Atomistic molecular dynamics simulations reveal the formation of nanojets with velocities up to 400 meters per second, created by pressurized injection of ßuid propane through nanoscale convergent gold nozzles with heating or coating of the nozzle exterior surface to prevent formation of thick block ..."
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Cited by 18 (0 self)
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Atomistic molecular dynamics simulations reveal the formation of nanojets with velocities up to 400 meters per second, created by pressurized injection of ßuid propane through nanoscale convergent gold nozzles with heating or coating of the nozzle exterior surface to prevent formation of thick blocking Þlms. The atomistic description is related to continuum hydrodynamic modeling through the derivation of a stochastic lubrication equation that includes thermally triggered ßuctuations whose inßuence on the dynamical evolution increases as the jet dimensions become smaller. Emergence of doublecone neck shapes is predicted when the jet approaches nanoscale molecular dimensions, deviating from the longthread universal similarity solution obtained in the absence of such ßuctuations. Liquid jets of macroscopic dimensions and their breakup into drops have been of great scientific interest (1, 2) and have been used in fuel injection (3), cutting and machining (4,
Global charges in ChernSimons theory and the 2+1 black hole
, 1995
"... We use the ReggeTeitelboim method to treat surface integrals in gauge theories to find global charges in ChernSimons theory. We derive the affine and Virasoro generators as global charges associated with symmetries of the boundary. The role of boundary conditions is clarified. We prove that for di ..."
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Cited by 15 (0 self)
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We use the ReggeTeitelboim method to treat surface integrals in gauge theories to find global charges in ChernSimons theory. We derive the affine and Virasoro generators as global charges associated with symmetries of the boundary. The role of boundary conditions is clarified. We prove that for diffeomorphisms that do not preserve the boundary there is a classical contribution to the central charge in the Virasoro algebra. The example of antide Sitter 2+1 gravity is considered in detail. I.
Scientific Alternatives to the Anthropic Principle
, 2007
"... Abstract It is explained in detail why the Anthropic Principle (AP) cannot yield any falsifiable predictions, and therefore cannot be a part of science. Cases which have been claimed as successful predictions from the AP are shown to be not that. Either they are uncontroversial applications of sele ..."
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Abstract It is explained in detail why the Anthropic Principle (AP) cannot yield any falsifiable predictions, and therefore cannot be a part of science. Cases which have been claimed as successful predictions from the AP are shown to be not that. Either they are uncontroversial applications of selection principles in one universe (as in Dicke's argument), or the predictions made do not actually logically depend on any assumption about life or intelligence, but instead depend only on arguments from observed facts (as in the case of arguments by Hoyle and Weinberg). The Principle of Mediocrity is also examined and shown to be unreliable, as arguments for factually true conclusions can easily be modified to lead to false conclusions by reasonable changes in the specification of the ensemble in which we are assumed to be typical. We show however that it is still possible to make falsifiable predictions from theories of multiverses, if the ensemble predicted has certain properties specified here. An example of such a falsifiable multiverse theory is cosmological natural selection. It is reviewed here and it is argued that the theory remains unfalsified. But it is very vulnerable to falsification by current observations, which shows that it is a scientific theory. The consequences for recent discussions of the AP in the context of string theory are discussed.