Simulazioni numeriche di modelli a grana grossa per dna a doppia e tripla elica

The aim of this thesis is to verify the thermodynamic proprierties of a double and triple stranded DNA and the existence of a melting temperature with a sharp phase transition from a bound state to two or three single stranded DNA. The DNA chains are represented by a Markov process in a direct lattice with 1+1, 2+1 or 3+1 dimensions where the Metropolis and the Wang-Landau algorithms are implemented. The Wang-Landau algorthm allows to estimate the density of states in energy space g(E) and with it the averange value of internal energy and the specific heat. The simulation results support the existence of a sharp phase transition only with a 3+1 dimensional lattice.