#### Table of contents

Bulg. J. Phys. vol. **40** no. 2 (2013)

**Development, Highlights, and Prospects of Plasma Physics Research in Bulgaria**

I. Zhelyazkov

pp. 085-092, [abs, pdf]

**Studying Quantum Field Theory**

I.T. Todorov

pp. 093-114, [abs, pdf]

**The**

*u(2)*and_{α}*su(2)*Hahn Harmonic Oscillators_{α}E.I. Jafarov, N.I. Stoilova, J. Van der Jeugt

pp. 115-120, [abs, pdf]

**Dynamical Volume Element in Scale-Invariant and Supergravity Theories**

E. Guendelman, E. Nissimov, S. Pacheva, M. Vasihoun

pp. 121-126, [abs, pdf]

**Dynamical Couplings and Charge Confinement/Deconfinement from Gravity Coupled to Nonlinear Gauge Fields**

E. Guendelman, A. Kaganovich, E. Nissimov, S. Pacheva

pp. 127-133, [abs, pdf]

**Lightlike Membranes in Black Hole and Wormhole Physics, and Cosmology**

E. Guendelman, A. Kaganovich, E. Nissimov, S. Pacheva

pp. 134-140, [abs, pdf]

**SU(n) WZNW fusion and a Q-algebra**

L. Hadjiivanov, P. Furlan

pp. 141-146, [abs, pdf]

**Correlation Functions of Conserved Currents in Four Dimensional Conformal Field Theory with Higher Spin Symmetry**

Ya.S. Stanev

pp. 147-152, [abs, pdf]

**Fermions as a Gauge Model Ground State**

M.N. Stoilov

pp. 153-158, [abs, pdf]

**On the Critical Behavior of the Inverse Susceptibility of a Model of Structural Phase Transitions**

E.S. Pisanova, S.I. Ivanov

pp. 159-164, [abs, pdf]

**Excitonic and Vibronic Spectra in 2D Molecular Quadratic Lattice**

I.J. Lalov, I. Zhelyazkov

pp. 165-175, [abs, pdf]