The renormalization group plays an essential role in many areas of physics, both
conceptually and as a practical tool to determine the long-distance low-energy properties of …

Various aspects of the Exact Renormalization Group (ERG) are explored, starting with a
review of the concepts underpinning the framework and the circumstances under which it is …

A short introduction is given on the functional renormalization group method, putting
emphasis on its nonperturbative aspects. The method enables to find nontrivial fixed points …

We reexamine the two-dimensional linear O (2) model (φ 4 theory) in the framework of the
nonperturbative renormalization-group. From the flow equations obtained in the derivative …

We study scaling solutions of the RG flow equation for $\mathbb {Z} _ {2} $-effective
potentials in a continuous dimension d⩾ 2. As the dimension is lowered from d= 4 we first …

The Berezinskii-Kosterlitz-Thouless (BKT) mechanism describes universal vortex unbinding
in many two-dimensional systems, including the paradigmatic XY model. However, most of …

We study the quantum sine-Gordon model within a nonperturbative functional
renormalization-group approach (FRG). This approach is benchmarked by comparing our …

The study of the Berezinskii-Kosterlitz-Thouless transition in two-dimensional| φ| 4 models
can be performed in several representations, and the amplitude-phase (AP) Madelung …

A bstract After showing how to prove the integrated c-theorem within the functional RG
framework based on the effective average action, we derive an exact RG flow equation for …

We employ the functional renormalization group framework at the second order in the
derivative expansion to study the $ O (N) $ models continuously varying the number of field …