7,391 research outputs found
Trigonometric Degeneration and Orbifold Wess-Zumino-Witten Model. I
Trigonometric degeneration of the Baxter-Belavin elliptic r matrix is
described by the degeneration of the twisted WZW model on elliptic curves. The
spaces of conformal blocks and conformal coinvariants of the degenerate model
are factorised into those of the orbifold WZW model.Comment: 24 pages, 1 figure, contribution to ``Conformal Field Theory and
Integrable Models'', Chernogolovka, Moscow Region, Russia, on September
15--21, 2002; typos corrected, references added (v2); typos corrected, final
version (v3
Inequality and risk aversion in health and income: an empirical analysis using hypothetical scenarios with losses
Four kinds of distributional preferences are explored: inequality aversion in health, inequality aversion in income, risk aversion in health, and risk aversion in income. Face to face interviews of a representative sample of the general public are undertaken using hypothetical scenarios involving losses in either health or income. Whilst in health risk aversion is stronger than inequality aversion, in the income context we cannot reject that attitudes to inequality aversion and risk aversion are the same. When we compare across contexts we find that inequality aversion and risk aversion are both stronger in income than they each are in health
Is more health always better? Exploring public preferences that violate monotonicity
Abásolo and Tsuchiya (2004a) report on an empirical study to elicit public preferences regarding the efficiency-equality trade-off in health, where the majority of respondents violated monotonicity. The procedure used has been subject to criticisms regarding potential biases in the results. The aim of this paper is to analyse whether violation of monotonicity remains when a revised questionnaire is used. We test: whether monotonicity is violated when we allow for inequality neutral preferences and also if we allow for preferences that would reject any option which gives no health gain to one group; whether those who violate monotonicity actually have non-monotonic or Rawlsian preferences; whether the titration sequence of the original questionnaire may have biased the results; whether monotonicity is violated when an alternative question is administered. Finally, we also test for symmetry of preferences. The results confirm the evidence of the previous study regarding violation of monotonicity
Abelian Conformal Field theories and Determinant Bundles
The present paper is the first in a series of papers, in which we shall
construct modular functors and Topological Quantum Field Theories from the
conformal field theory developed in [TUY].
The basic idea is that the covariant constant sections of the sheaf of vacua
associated to a simple Lie algebra over Teichm\"uller space of an oriented
pointed surface gives the vectorspace the modular functor associates to the
oriented pointed surface. However the connection on the sheaf of vacua is only
projectively flat, so we need to find a suitable line bundle with a connection,
such that the tensor product of the two has a flat connection.
We shall construct a line bundle with a connection on any family of pointed
curves with formal coordinates. By computing the curvature of this line bundle,
we conclude that we actually need a fractional power of this line bundle so as
to obtain a flat connection after tensoring. In order to functorially extract
this fractional power, we need to construct a preferred section of the line
bundle.
We shall construct the line bundle by the use of the so-called -ghost
systems (Faddeev-Popov ghosts) first introduced in covariant quantization [FP].
We follow the ideas of [KNTY], but decribe it from the point of view of [TUY].Comment: A couple of typos correcte
USp(2k) Matrix Model: Schwinger-Dyson Equations and Closed-Open String Interactions
We derive the Schwinger-Dyson/loop equations for the USp(2k) matrix model
which close among the closed and open Wilson loop variables. These loop
equations exhibit a complete set of the joining and splitting interactions
required for the nonorientable Type I superstrings. The open loops realize the
SO(2n_f) Chan-Paton factor and their linearized loop equations derive the mixed
Dirichlet/Neumann boundary conditions.Comment: 22 pages, 13 figure
Quantum Gravity and Black Hole Dynamics in 1+1 Dimensions
We study the quantum theory of 1+1 dimensional dilaton gravity, which is an
interesting toy model of the black hole dynamics. The functional measures are
explicitly evaluated and the physical state conditions corresponding to the
Hamiltonian and the momentum constraints are derived. It is pointed out that
the constraints form the Virasoro algebra without central charge. In ADM
formalism the measures are very ambiguous, but in our formalism they are
explicitly defined. Then the new features which are not seen in ADM formalism
come out. A singularity appears at \df^2 =\kappa (>0) , where and is the number of matter fields. Behind the singularity
the quantum mechanical region \kappa > \df^2 >0 extends, where the sign of
the kinetic term in the Hamiltonian constraint changes. If , the
singularity disappears. We discuss the quantum dynamics of black hole and then
give a suggestion for the resolution of the information loss paradox. We also
argue the quantization of the spherically symmetric gravitational system in 3+1
dimensions. In appendix the differences between the other quantum dilaton
gravities and ours are clarified and our status is stressed.Comment: phyztex, UT-Komaba 92-14. A few misleading sentences are corrected
and some references are adde
Exact Results in N_c=2 IIB Matrix Model
We investigate N_c=2 case of IIB matrix model, which is exactly soluble. We
calculate the partition function exactly and obtain a finite result without
introducing any cut-off. We also evaluate some correlation functions consisting
of Wilson loops.Comment: 8 pages, Late
- …