Related papers: Mass Generation in the Large N nonlinear sigma-Mod…
We develop a path-integral formalism to study the formation of large-scale structures in the universe. Starting from the equations of motion of hydrodynamics (single-stream approximation) we derive the action which describes the statistical…
The quantum field theory describing the massive O(2) nonlinear sigma-model is investigated through two non-perturbative constructions: The form factor bootstrap based on integrability and the lattice formulation as the XY model. The…
The self-energy of the critical 3-dimensional O(N) model is calculated. The analysis is performed in the context of the Non-Perturbative Renormalization Group, by exploiting an approximation which takes into account contributions of an…
Structure Functions for small DIS (deep inelastic scattering) $x$ for integrable models are investigated, in particular, for the $O(N)$~$\sigma $-model and $SU(N)$ chiral Gross-Neveu model, which are asymptotically free. We get the…
We study periodically driven bosonic scalar field theories in the infinite N limit. It is well-known that the free theory can undergo parametric resonance under monochromatic modulation of the mass term and thereby absorb energy…
In this paper we study a family of nonlinear $\sigma$-models in which the target space is the super manifold $H^{2|2N}$. These models generalize Zirnbauer's $H^{2|2}$ nonlinear $\sigma$-model which has a number of special features for which…
Using superfield Dyson-Schwinger equations, we compute the infrared dynamics of the semi-amputated full vertex, corresponding to the effective running gauge coupling, in N-flavour {\mathcal N}=1 supersymmetric QED(3). It is shown that the…
We review applications of the sine-Gordon model, the O(3) non-linear sigma model, the U(1) Thirring model, and the O(N) Gross--Neveu model to quasi one-dimensional quantum magnets, Mott insulators, and carbon nanotubes. We focus upon the…
In this paper we build a family of heterotic deformations of the O(N) sigma model. These deformations break (1,1) supersymmetry down to (0,1) symmetry. We solve this model at large N. We also find an alternative superfield formulation of…
We develop numerical tools for Diagrammatic Monte-Carlo simulations of non-Abelian lattice field theories in the t'Hooft large-N limit based on the weak-coupling expansion. First we note that the path integral measure of such theories…
We present a direct derivation of the thermodynamic integral equations of the O(3) nonlinear $\sigma$-model in two dimensions.
Because mass loss is a fundamental phenomenon in massive stars, interaction with circumstellar material (CSM) should be universal in core-collapse supernovae (SNe). Leaving aside the extreme CSM density, extent, or mass typically…
We consider the effective potential in three-dimensional models with O(N) symmetry. For generic values of N, and in particular for the physically interesting cases N=0,1,2,3, we determine the six-point and eight-point renormalized coupling…
The out-of-equilibrium dynamics of the O(N+1) nonlinear sigma model in 1+1 dimensions is investigated in the large N limit. Regarding the nonlinearity as the effect of a suitable large coupling limit of the O(N+1) \phi^4 model, we first of…
We show that the infinite series in the classical action for non(anti)commutative N=2 sigma models in two dimensions, can be resummed by using constraint equations of the auxiliary fields. We argue that the resulting action takes a standard…
We extend our investigation on a possible de Sitter symmetry breaking mechanism in non-linear sigma models. The scale invariance of the quantum fluctuations could make the cosmological constant time dependent signaling the de Sitter…
In this talk we present a numerical lattice study of an SU(3) gauge model where an SU(2) doublet of non-Abelian strongly interacting fermions is coupled to a complex scalar field doublet via a Yukawa and a Wilson-like term. The model enjoys…
We analyze $(2+1)$-dimensional vector-vector type four-Fermi interaction (Thirring) model in the framework of the $1/N$ expansion. By solving the Dyson-Schwinger equation in the large-$N$ limit, we show that in the two-component formalism…
SU(2) gauge theory with Nf=24 massless fermions is non-interacting at long distances, i.e. it has an infrared fixed point at vanishing coupling. With massive fermions the fermions are expected to decouple at energy scales below the fermion…
We consider the Nelson model with ultraviolet cutoff, which describes the interaction between non-relativistic particles and a positive or zero mass quantized scalar field. We take the non-relativistic particles to obey Fermi statistics and…