31,774 research outputs found
Virasoro Orbits, AdS_3 Quantum Gravity and Entropy
We analyse the canonical structure of AdS_3 gravity in terms of the coadjoint
orbits of the Virasoro group. There is one subset of orbits, associated to BTZ
black hole solutions, that can be described by a pair of chiral free fields
with a background charge. There is also a second subset of orbits, associated
to point-particle solutions, that are described by two pairs of chiral free
fields obeying a constraint. All these orbits admit K\"ahler quantization and
generate a Hilbert space which, despite of having ,
does not provide the right degeneracy to account for the Bekenstein-Hawking
entropy due to the breakdown of modular invariance. Therefore, additional
degrees of freedom, reestablishing modular invariance, are necessarily required
to properly account for the black hole entropy.Comment: LaTex file, 12 pages. New references adde
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The hidden potential of "managerial macroeconomics" for CEO decision making in MBA programs
Macroeconomics has profound strategic and tactical implications for CEO decision making, yet many top-ranked business schools do not offer this subject in its appropriately integrative and applied management context. I illustrate how the careful cultivation of "macroeconomic literacy" in the MBA classroom using four innovative instructional strategies can improve CEO decision making across all functional areas of the firm while helping to meet important AACSB learning goals, including curriculum integration, application of interactive teaching strategies, soft skills enhancement, and promoting a global perspective. © Academy of Management Learning & Education, 2006
A Note on Einstein Gravity on AdS and Boundary Conformal Field Theory
We find a simple relation between the first subleading terms in the
asymptotic expansion of the metric field in AdS, obeying the Brown-Henneaux
boundary conditions, and the stress tensor of the underlying Liouville theory
on the boundary. We can also provide an more explicit relation between the bulk
metric and the boundary conformal field theory when it is described in terms of
a free field with a background charge.Comment: LateX file, 10 page
Reflexive functors of modules in Commutative Algebra
Reflexive functors of modules naturally appear in Algebraic Geometry, mainly
in the theory of linear representations of group schemes, and in "duality
theories". In this paper we study and determine reflexive functors and we give
many properties of reflexive functors
Moduli Spaces and Formal Operads
Let overline{M}_{g,n} be the moduli space of stable algebraic curves of genus
g with n marked points. With the operations which relate the different moduli
spaces identifying marked points, the family (overline{M}_{g,n})_{g,n} is a
modular operad of projective smooth Deligne-Mumford stacks, overline{M}. In
this paper we prove that the modular operad of singular chains
C_*(overline{M};Q) is formal; so it is weakly equivalent to the modular operad
of its homology H_*(overline{M};Q). As a consequence, the "up to homotopy"
algebras of these two operads are the same. To obtain this result we prove a
formality theorem for operads analogous to Deligne-Griffiths-Morgan-Sullivan
formality theorem, the existence of minimal models of modular operads, and a
characterization of formality for operads which shows that formality is
independent of the ground field.Comment: 36 pages (v3: some typographical corrections
A Shifting Landscape: A Decade of Change in American Attitudes about Same-Sex Marriage and LGBT Issues
This national survey of more than 4,500 Americans finds that support for allowing gay and lesbian people to legally wed has jumped 21 percentage points over the last decade, from 32 percent in 2003 to 53 percent in 2013, transforming the American religious landscape in the process
Majorana vs Pseudo-Dirac Neutrinos at the ILC
Neutrino masses could originate in seesaw models testable at colliders, with
light mediators and an approximate lepton number symmetry. The minimal model of
this type contains two quasi-degenerate Majorana fermions forming a
pseudo-Dirac pair. An important question is to what extent future colliders
will have sensitivity to the splitting between the Majorana components, since
this quantity signals the breaking of lepton number and is connected to the
light neutrino masses. We consider the production of these neutral heavy
leptons at the ILC, where their displaced decays provide a golden signal: a
forward-backward charge asymmetry, which depends crucially on the mass
splitting between the two Majorana components. We show that this observable can
constrain the mass splitting to values much lower than current bounds from
neutrinoless double beta decay and natural loop corrections.Comment: 16 pages, 5 figures; v2: Minor changes, version accepted for
publication in EPJ
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