2,809 research outputs found
Simplifying Algebra in Feynman Graphs, Part III: Massive Vectors
A T-dualized selfdual inspired formulation of massive vector fields coupled
to arbitrary matter is generated; subsequently its perturbative series modeling
a spontaneously broken gauge theory is analyzed. The new Feynman rules and
external line factors are chirally minimized in the sense that only one type of
spin index occurs in the rules. Several processes are examined in detail and
the cross-sections formulated in this approach. A double line formulation of
the Lorentz algebra for Feynman diagrams is produced in this formalism, similar
to color ordering, which follows from a spin ordering of the Feynman rules. The
new double line formalism leads to further minimization of gauge invariant
scattering in perturbation theory. The dualized electroweak model is also
generated.Comment: 39 pages, LaTeX, 8 figure
Holographic Normal Ordering and Multi-particle States in the AdS/CFT Correspondence
The general correlator of composite operators of N=4 supersymmetric gauge
field theory is divergent. We introduce a means for renormalizing these
correlators by adding a boundary theory on the AdS space correcting for the
divergences. Such renormalizations are not equivalent to the standard normal
ordering of current algebras in two dimensions. The correlators contain contact
terms that contribute to the OPE; we relate them diagrammatically to
correlation functions of compound composite operators dual to multi-particle
states.Comment: 18 pages, one equation corr., further comments and refs. adde
Some Cubic Couplings in Type IIB Supergravity on and Three-point Functions in SYM_4 at Large N
All cubic couplings in type IIB supergravity on that
involve two scalar fields that are mixtures of the five form field
strength on and the trace of the graviton on are derived by using
the covariant equations of motion and the quadratic action for type IIB
supergravity on . All corresponding three-point functions in
SYM are calculated in the supergravity approximation. It is pointed out
that the scalars correspond not to the chiral primary operators in the
SYM but rather to a proper extension of the operators.Comment: Latex, 24p, misprints are correcte
Three-point Green function of the stress-energy tensor in the AdS/CFT correspondence
We compute the 3-point function of the stress-energy tensor in the
d-dimensional CFT from the AdS_{d+1} gravity. For d=4 the coefficients of the
three linearly independent conformally covariant forms entering the 3-point
function are exactly the same as given by the free field computations in the
SYM just as expected from the known renormalization theorems. For
d=3 and d=6 our results give the value of the corresponding 3-point function in
the theories of strongly coupled superconformal scalar and (2,0)
tensor multiplets respectively.Comment: Latex, 13 pages, eq. (2.10) is correcte
Cubic Twistorial String Field Theory
Witten has recently proposed a string theory in twistor space whose
D-instanton contributions are conjectured to compute N=4 super-Yang-Mills
scattering amplitudes. An alternative string theory in twistor space was then
proposed whose open string tree amplitudes reproduce the D-instanton
computations of maximal degree in Witten's model.
In this paper, a cubic open string field theory action is constructed for
this alternative string in twistor space, and is shown to be invariant under
parity transformations which exchange MHV and googly amplitudes. Since the
string field theory action is gauge-invariant and reproduces the correct cubic
super-Yang-Mills interactions, it provides strong support for the conjecture
that the string theory correctly computes N-point super-Yang-Mills tree
amplitudes.Comment: 19+1 pages, 4+1 EPS figures, JHEP3 LaTeX; v2: minor corrections,
references added; v3: the final version published in JHEP with a new footnote
on the d=0 on-shell contributio
Can Modal Skepticism Defeat Humean Skepticism?
My topic is moderate modal skepticism in the spirit of Peter van Inwagen. Here understood, this is a conservative version of modal empiricism that severely limits the extent to which an ordinary agent can reasonably believe âexoticâ possibility claims. I offer a novel argument in support of this brand of skepticism: modal skepticism grounds an attractive (and novel) reply to Humean skepticism. Thus, I propose that modal skepticism be accepted on the basis of its theoretical utility as a tool for dissolving philosophical paradox
The Operator Product Expansion for Wilson Loops and Surfaces in the Large N Limit
The operator product expansion for ``small'' Wilson loops in {\cal N}=4, d=4
SYM is studied. The OPE coefficients are calculated in the large N and g_{YM}^2
N limit by exploiting the AdS/CFT correspondence. We also consider Wilson
surfaces in the (0,2), d=6 superconformal theory. In this case, we find that
the UV divergent terms include a term proportional to the rigid string action.Comment: 22 pages LaTeX2e, using utarticle.cls (included) and AMS-LaTeX macro
The Real Combination Problem : Panpsychism, Micro-Subjects, and Emergence
Panpsychism harbors an unresolved tension, the seriousness of which has yet to be fully appreciated. I capture this tension as a dilemma, and offer panpsychists advice on how to resolve it. The dilemma, briefly, is as follows. Panpsychists are committed to the perspicuous explanation of macro-mentality in terms of micro-mentality. But panpsychists take the micro-material realm to feature not just mental properties, but also micro-subjects to whom these properties belong. Yet it is impossible to explain the constitution of a macro-subject (like one of us) in terms of the assembly of micro-subjects, for, I show, subjects cannot combine. Therefore the panpsychist explanatory project is derailed by the insistence that the worldâs ultimate material constituents (ultimates) are subjects of experience. The panpsychist faces a choice of abandoning her explanatory project, or recanting the claim that the ultimates are subjects. This is the dilemma. I argue that the latter option is to be preferred. This neednât constitute a wholesale abandonment of panpsychism, however, since panpsychists can maintain that the ultimates possess phenomenal qualities, despite not being subjects of those qualities. This proposal requires us to make sense of phenomenal qualities existing independently of experiencing subjects, a challenge I tackle in the penultimate section. The position eventually reached is a form of neutral monism, so another way to express the overall argument is to say that, keeping true to their philosophical motivations, panpsychists should really be neutral monists.Peer reviewedFinal Accepted Versio
Russellian Monism and Mental Causation
© 2019 Wiley Periodicals, Inc.According to Russellian monism, consciousness is constituted at least partly by quiddities: intrinsic properties that categorically ground dispositional properties described by fundamental physics. If the theory is true, then consciousness and such dispositional properties are closely connected. But how closely? The contingency thesis says that the connection is contingent. For example, on this thesis the dispositional property associated with negative charge might have been categorically grounded by a quiddity that is distinct from the one that actually grounds it. Some argue that Russellian monism entails the contingency thesis and that this makes its consciousnessâconstituting quiddities epiphenomenalâa disastrous outcome for a theory that is motivated partly by its prospects for integrating consciousness into physical causation. We consider two versions of that argument, a generic version and an intriguing version developed by Robert J. Howell, which he bases on Jaegwon Kim's wellâknown âexclusion argument.â We argue that neither succeeds.Peer reviewe
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