Universitat Polite(cid:181)cnica de Catalunya Path integral Monte Carlo Algorithms and applications to quantum (cid:176)uids Llorenc» Brualla i Barber(cid:181)a Doctoral Dissertation Departament de Fisica i Enginyeria Nuclear Barcelona 2002 Path integral Monte Carlo Algorithms and applications to quantum (cid:176)uids Llorenc» Brualla i Barber(cid:181)a Universitat Polit(cid:181)ecnica de Catalunya Path integral Monte Carlo Algorithms and applications to quantum (cid:176)uids Path integral Monte Carlo Algorithms and applications to quantum (cid:176)uids Llorenc» Brualla i Barber(cid:181)a Mem(cid:181)oria presentada per optar al grau de Doctor en Ci(cid:181)encies Fisiques July 16, 2002 Universitat Polit(cid:181)ecnica de Catalunya The programs in this book have been included for their instructional value. They have been tested with care but are not guaranteed for any particular purpose. The author does not ofier any warranties or representations, nor does he accept any liabilities with respect to the programs Cover: PIMC simulation of liquid 4He at 5 K, 64 atoms with 8 beads per atom Typeset by the author with the LATEX Documentation System Copyright c 2002 by Llorenc» Brualla i Barber(cid:181)a. (cid:176) All rights reserved. This book, or parts thereof, may not be reproduced in any form or by any means, electronic or mechanical, including photocopying, recording or any information storage and retrieval system now known or to be invented, without written permission from the author. To Teresa Miserabile. Aveva sopra il capo l’unico luogo stabile del cosmo, l’unico riscatto alla dannazione del panta rei, e pensava che fossero afiari Suoi, e non suoi. E infatti subito dopo la coppia si allontan(cid:181)o|lui educato su qualche manuale che gli aveva ottenebrato la possibilit(cid:181)a di meraviglia, lei inerte, inaccessibile al brivido dell’inflnito, entrambi senza aver registrato nella propria memoria l’esperienza terriflcante di quel loro incontro|primo e ultimo|con l’Uno, l’En{sof, l’Indicibile. Come non cadere in ginocchio davanti all’altare della certezza? (Umberto Eco, Il pendolo di Foucault, 1988)