Related papers: On the equivalence between 2D Yukawa and Gross-Nev…
We investigate on the lattice the Yukawa models in 2 dimensions with Z(2) and U(1) symmetries. These models reduce to the usual and chiral Gross-Neveu models, respectively, when the kinetic and the selfcoupling terms of the scalar field are…
We describe a 4D U(1) lattice gauge theory with charged scalar $\phi$ and fermion $\chi$ matter fields ($\chi U \phi$ model). At sufficiently strong gauge coupling, the chiral symmetry is broken and the mass of the unconfined composite…
We investigate numerically on the lattice the interplay of universality classes of the three-dimensional Yukawa model with U(1) chiral symmetry, using the Binder method of finite size scaling. At zero Yukawa coupling the scaling related to…
We present numerical evidence that the 2d Yukawa models with strong quartic selfcoupling of the scalar field have the same phase structure and are asymptotically free in the Yukawa coupling like the Gross-Neveu models.
By means of the Lee-Shrock transformation we generalize the 2D Gross-Neveu (GN$_2$) model to a U(1) gauge theory with charged fermion and scalar fields in 2D ($\chi U \phi_2$ model). The $\chi U \phi_2$ model is equivalent to the GN$_2$…
Evidence for the same universal behavior of 2d Yukawa and Gross-Neveu models in a certain range of couplings, particularly for $\kappa<0$, is presented.
We investigate the Yukawa model in which $N_f$ fermions are coupled with a scalar field $\phi$ through a Yukawa interaction. The phase diagram is rather well understood. If the fermions are massless, there is a chiral transition at $T_c$:…
We generalize the $N_F=2$ Schwinger model on the lattice by adding a charged scalar field. In this so-called $\chi U\phi_2$ model the scalar field shields the fermion charge, and a neutral fermion, acquiring mass dynamically, is present in…
The 3D Yukawa model with U(1) chiral symmetry is investigated in a broad interval of parameters using the Binder method. Critical exponents of the Wilson-Fisher (magnetic) and Gross-Neveu (chiral) universality classes are measured. The…
We study conformal field theories with Yukawa interactions in dimensions between 2 and 4; they provide UV completions of the Nambu-Jona-Lasinio and Gross-Neveu models which have four-fermion interactions. We compute the sphere free energy…
We discuss models with a massless fermion and a self-interacting massive scalar field with the Yukawa interaction. The chiral condensate and the fermion mass are calculated analytically. It is shown that the models have a phase transition…
We measure the critical exponents of the three dimensional Gross-Neveu model with two four-component fermions. The exponents are inferred from the scaling behaviour of observables on different lattice sizes. We also calculate the exponents,…
We study an asymptotically free theory of $N$ relativistic Dirac fermions and a real scalar field coupled by Yukawa and scalar self-interactions in three dimensions using functional renormalisation. In the limit of many fermion flavours,…
The $\rm SU(2)_L\otimes SU(2)_R$ symmetric Yukawa model with mirror-fermions in the limit where the mirror-fermion is decoupled is studied both analytically and numerically. The bare scalar self-coupling $\lambda$ is fixed at zero and…
We use the epsilon expansion to explore a new universality class of second order quantum phase transitions associated with a four-dimensional Yukawa field theory coupled to a traceless Hermitean matrix scalar field. We argue that this class…
We summarize our recent study of the fermion spectrum in a fermion-scalar 2D model with a chiral $U(1)_L \times U(1)_R$ global symmetry. This model is obtained from a two-cutoff lattice formulation of a 2D U(1) chiral gauge theory, in the…
We consider the fermion spectrum in the strong coupling vortex phase of a lattice fermion-scalar model with a global $U(1)_L\times U(1)_R$, in 2D, in the context of a recently proposed two-cutoff lattice formulation. The fermion doublers…
Dynamical chiral symmetry breaking in a strongly coupled U(1) lattice gauge model with charged fermions and scalar is investigated by numerical simulation. Several composite neutral states are observed, in particular a massive fermion. In…
We investigate the finite-temperature behavior of the Yukawa model in which $N_{f}$ fermions are coupled with a scalar field $\phi$ in the limit $N_f \to \infty$. Close to the chiral transition the model shows a crossover between mean-field…
We perform a numerical bootstrap study of scalar operators in the critical 3d Gross-Neveu-Yukawa models, a family of conformal field theories containing N Majorana fermions in the fundamental representation of an O(N) global symmetry. We…