Policymakers, researchers, and practitioners discuss the role of central counterparties

This article summarizes a conference, titled “Issues Related to Central Counterparty Clearing,” cosponsored by the Federal Reserve Bank of Chicago and the European Central Bank on April 3–4, 2006. The conference brought together industry executives, policymakers, and research economists to evaluate current public policy issues involving central counterparties.Banks and banking, Central ; Risk management ; Clearinghouses (Banking)

Non-Commutative Yang-Mills and the AdS/CFT Correspondence

We study the non-commutative supersymmetric Yang-Mills theory at strong coupling using the AdS/CFT correspondence. The supergravity description and the UV/IR relation confirms the expectation that the non-commutativity affects the ultra-violet but not the infra-red of the Yang-Mills dynamics. We show that the supergravity solution dual to the non-commutative N=4 SYM in four dimensions has no boundary and defines a minimal scale. We also show that the relation between the B field and the scale of non-commutativity is corrected at large coupling and determine its dependence on the 't Hooft coupling \lambda.Comment: 9 pages, 1 figure, References and comments added, typos correcte

Two-dimensional dilaton gravity in a unitary gauge

Reduced phase space formulation of CGHS model of 2d dilaton gravity is studied in en extrinsic time gauge. The corresponding Hamiltonian can be promoted into a Hermitian operator acting in the physical Hilbert space, implying a unitary evolution for the system. Consequences for the black hole physics are discussed. In particular, this manifestly unitary theory rules out the Hawking scenario for the endpoint of the black hole evaporation process.Comment: 12 pages, LaTex file, Imperial-TP/92-93/8 and QMW/PH/92/1

A Note on Effective Lagrangians in Matrix Theory

We study the relation between the effective Lagrangian in Matrix Theory and eleven dimensional supergravity. In particular, we provide a relationship between supergravity operators and the corresponding terms in the post-Newtonian approximation of Matrix Theory.Comment: 7 pages, use harvmac. References adde

Flux Stabilization of D-branes in NSNS Melvin Background

In this paper we reexamine the D-brane spectrum in the Melvin background with nonconstant NSNS B-field from the viewpoint of its world-volume and string world-sheet theory. We find that the stable D2-D0 bound state exists even though it does not wrap any nontrivial cycles. We show that this system is stabilized by the presence of the NSNS B-field and the magnetic flux F. Moreover from the non-abelian world-volume theory of D0-branes the bound state is regarded as a system of D0-branes expanding into a fuzzy torus.Comment: Latex, 13 pages, 1 figure, references added and minor corrections(v2), one comment added, to appear in PLB(v3

A Note on the Transverse Five-Brane in M(atrix) Theory

We describe a way to compute scattering amplitudes in M(atrix) quantum mechanics, that involve the transverse five-brane. We then compute certain scattering processes and show that they have the expected SO(5) invariance, give the correct transverse-five-brane mass, and agree with the supergravity result.Comment: 13 pages, Latex, final version to appear in PL

Scattering of zero branes off elementary strings in Matrix Theory

We consider the scattering of zero branes off an elementary string in Matrix theory or equivalently gravitons off a longitudinally wrapped membrane. The leading supergravity result is recovered by a one-loop calculation in zero brane quantum mechanics. Simple scaling arguments are used to show that there are no further corrections at higher loops, to the leading term in the large impact parameter, low velocity expansion. The mechanism for this agreement is identified in terms of properties of a recently discovered boundary conformal field theory.Comment: 16 pages (harvmac big), 2 figures, references adde