20 Result(s)

Article

W ₄ toda example as hidden Liouville CFT

We construct correlators in the W ₄ Toda 2d conformal field theory for a particular class of representations and demonstrate a relation to a W ₂ (Vi...

P. Furlan, V. B. Petkova in Physics of Particles and Nuclei Letters (2017)

Article

Topological defects in CFT

Areview of the notion, properties and the use of topological defects in 2d conformal field theories is presented. An emphasis is made on the recent interpretation of such operators in non-rational theories, as...

V. B. Petkova in Physics of Atomic Nuclei (2013)

Article

Hydrogels based on polycarboxylic acid-agar-agar complexes

IR spectroscopy and viscometry data have shown that poly(acrylic acid) and poly(methacrylic acid) form complexes with agar-agar in aqueous solutions as they do with other polysaccharides. The polyacid-agar-aga...

V. Yu. Baranovskii, V. G. Ganev, V. B. Petkova, Kh. Ch. Voicheva… in Colloid Journal (2012)

Article

On the crossing relation in the presence of defects

The OPE of local operators in the presence of defect lines is considered both in the rational CFT and the c > 25 Virasoro (Liouville) theory. The duality transformation of the 4-point function with inserted defec...

V. B. Petkova in Journal of High Energy Physics (2010)

Article

A pharmacoeconomical model for choice of a treatment for pregnant women with gestational diabetes

This study discusses two main questions: the direct medical costs and the clinical effectiveness of the hospital treatment with insulin of pregnant women with gestational diabetes (GD). A prospective study tha...

K. Todorova, O. Palaveev, V. B. Petkova, M. Stefanova, Zl. Dimitrova in Acta Diabetologica (2007)

Article

Pilot project for education of patients with type 2 diabetes by pharmacists

The objective was to adapt and test an educational programme for type 2 diabetes patients. The sample consisted of 24 individuals with type 2 diabetes between 31 and 75 years of age that did not require insuli...

V. B. Petkova, G.I. Petrova in Acta Diabetologica (2006)

Article

Bulk Correlation Functions in 2d Quantum Gravity

We compute the bulk three- and four-point tachyon correlators in the 2d Liouville gravity with a nonrational matter central charge c < 1, using and comparing two approaches. The continuous CFT approach exploit...

I. K. Kostov, V. B. Petkova in Theoretical and Mathematical Physics (2006)

Article

An Extension of the Character Ring of sl(3) and Its Quantisation

We construct a commutative ring with identity which extends the ring of characters of finite dimensional representations of sl(3). It is generated by characters with values in the group ring ...

P. Furlan, A. C. Ganchev, V. B. Petkova in Communications in Mathematical Physics (1999)

Chapter

On the “Drinfeld-Sokolov” Reduction of the Knizhnik-Zamolodchikov Equation

Even though the Hamiltonian reduction of two dimensional integrable and conformal theories has been a focus of much attention lately [1] the quantum aspect of the problem is in a more undeveloped stage. It has...

P. Furlan, A. Ch. Ganchev, R. Paunov… in Low-Dimensional Topology and Quantum Field… (1993)

Chapter and Conference Paper

U _q (sl(2)) Invariant operators and reduced polynomial identities

The existence of U _q (sl(2)) invariant operators for q ^P = 1 leads to relations for the quantum Clebsch - Gordan kernels and for the quantum 6j-symbo...

A. Ch. Ganchev, V. B. Petkova in Quantum Groups (1990)

Chapter and Conference Paper

All positive energy unitary irreducible representations of the extended conformal superalgebra

V. K. Dobrev, V. B. Petkova in Conformal Groups and Related Symmetries Ph… (1986)

Chapter and Conference Paper

Reducible representations of the extended conformal superalgebra and invariant differential operators

V. K. Dobrev, V. B. Petkova in Conformal Groups and Related Symmetries Ph… (1986)

Article

On the group-theoretical approach to extended conformal supersymmetry: Classification of multiplets

Physically important multiplets of indecomposable representations of the conformal superalgebra su(2, 2/N) are constructed and classified adapting results of Kac. Each multiplet exhausts, in particular, all super...

V. K. Dobrev, V. B. Petkova in Letters in Mathematical Physics (1985)

Article

Conformal gauges and renormalized equations of motion in massless quantum electrodynamics

A formulation of massless QED is studied with a non-singular Lagrangian and conformal invariant equations of motion. It makes use of non-decomposable representations of the conformal groupG and involves two dimen...

V. B. Petkova, G. M. Sotkov, I. T. Todorov in Communications in Mathematical Physics (1985)

Article

Conformal quantum electrodynamics and nondecomposable representations

P. Furlan, V. B. Petkova, G. M. Sotkov… in La Rivista del Nuovo Cimento (1978-1999) (1985)

Chapter

Conformal Gauges and Renormalized Equations of Motion in Massless Quantum Electrodynamics

A formulation of massless QED is studied with a non-singular Lagrangian and conformal invariant equations of motion. It makes use of non- decomposable representations of the conformal group G and involves two ...

V. B. Petkova, G. M. Sotkov, I. T. Todorov in Quantum Field Theory (1985)

Article

The six-point families of exceptional representations of the conformal group

Six-point families of topological reducible (indecomposable) representations of the conformal group of space-time M ₄ are studies. The structure of invariant subspaces is analysed and the full set of equivalence ...

V. B. Petkova, G. M. Sotkov in Letters in Mathematical Physics (1984)

Article

Z ₂ monopoles in the standardSU (2) lattice gauge theory model

The standardSU(2) lattice gauge theory model without fermions may be considered as aZ ₂ model with monopoles and fluctuating coupling constants. At low temperatures β⁻¹ (=small bare coupling constant) the monopol...

G. Mack, V. B. Petkova in Zeitschrift für Physik C Particles and Fields (1982)