We study QCD with two flavours of colour-sextet quarks as a candidate walking-Technicolor theory. We simulate lattice QCD with two flavours of colour-sextet staggered quarks at finite temperatures to observe the scales of confinement and chiral-symmetry breaking. These should give us some indication as to whether the massless theory has an infrared fixed point making it a conformal field theory...

In this article we compute the black hole entropy by finding a classical central charge of the Virasoro algebra of a Liouville theory using the Cardy formula. This is done by performing a dimensional reduction of the Einstein Hilbert action with the ansatz of spherical symmetry and writing the metric in conformally flat form. We obtain two coupled field equations. Using the near horizon approxi...

Recently, we have studied the general Virasoro construction at one loop in the background of the general non-linear sigma model. Here, we find the action formulation of these new conformal field theories when the background sigma model is itself conformal. In this case, the new conformal field theories are described by a large class of new spin-two gauged sigma models. As examples of the new ac...

Introducing an effective refraction index of an isotropic cosmic medium, we investigate the cosmological fluid dynamics which is consistent with a conformal, timelike symmetry of a corresponding “optical” metric. We demonstrate that this kind of symmetry is compatible with the existence of a negative viscous pressure and, consequently, with cosmological entropy production. We establish an exact...

A new class of time-symmetric solutions to the initial value constraints of vacuum General Relativity is introduced. These data are globally regular, asymptotically flat (with possibly several asymptotic ends) and in general have no isometries, but a U(1) × U(1) group of conformal isometries. After decomposing the Lichnerowicz conformal factor in a double Fourier series on the group orbits, the...

We show that the SU(N), level-1 Wess-Zumino-Witten conformal field theory provides a natural realization of the Yangian Y(sl~) for N _> 3. We also construct a hamiltonian/-/2 which commutes with the Yangian generators and study its spectrum. Our results, which generalize work by Haldane et al. [ 1 ], provide the field theory extension of the algebraic structure of the SU(N) Haldane-Shastry spin...

On the space of three-dimensional conformal field theories with U(1) symmetry and a chosen coupling to a background gauge field, there is a natural action of the group SL(2,Z). The generator S of SL(2,Z) acts by letting the background gauge field become dynamical, an operation considered recently by Kapustin and Strassler. The other generator T acts by shifting the Chern-Simons coupling of the ...

We re-examine the question of radiative symmetry breaking in the standard model in the presence of right-chiral neutrinos and a minimally enlarged scalar sector. We demonstrate that, with these extra ingredients, the hypothesis of classically unbroken conformal symmetry, besides naturally introducing and stabilizing a hierarchy, is compatible with all available data; in particular, there exists...

In holographic models of cosmology based on the (A)dS/CFT correspondence, conformal symmetry is implicit in the dual description of the Universe. Generically, however, one cannot expect the (broken) conformal invariance in the cosmic fluctuations as only the scale invariance is manifest in experiments. Also, in order for the prediction of the holographic models to make sense, the conformal symm...

We study finite-dimensional extra symmetries of generic 2D dilaton gravity models. Using a non-linear sigma model formulation we show that the unique theories admitting an extra (conformal) symmetry are the models with an exponential potential V ∝ e (S = 1 2π ∫ d2x √−g[Rφ + 4λ2eβφ]), which include the model of Callan, Giddings, Harvey and Strominger (CGHS) as a particular though limiting (β = 0...