WorldCat Identities

Universitat de Barcelona Departament d'Estructura i Constituents de la Matèria

Overview
Works: 207 works in 398 publications in 3 languages and 428 library holdings
Classifications: QC21.2,
Publication Timeline
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Most widely held works by Universitat de Barcelona
Fonaments de física by J. I Latorre( Book )

2 editions published between 1995 and 1998 in Catalan and held by 10 WorldCat member libraries worldwide

Problemes resolts de fonaments de física I by Jordi Ortín( Book )

3 editions published between 2000 and 2008 in Catalan and held by 10 WorldCat member libraries worldwide

Mecànica quàntica by Lluís Garrido Beltrán( Book )

3 editions published between 2006 and 2012 in Catalan and held by 9 WorldCat member libraries worldwide

Introducció a la física experimental : laboratori de termodinàmica by Lluís Mañosa( Book )

3 editions published between 2003 and 2005 in Catalan and held by 8 WorldCat member libraries worldwide

Problemes de termodinàmica by Eduard Vives i Santa Eulàlia( Book )

4 editions published between 1997 and 2000 in Catalan and held by 8 WorldCat member libraries worldwide

Anàlisi matemàtica d'una variable by Bruno Juliá-Diaz( Book )

1 edition published in 2012 in Catalan and held by 7 WorldCat member libraries worldwide

The Cathedrals of science CERN 1954-2004( Visual )

1 edition published in 2007 in Catalan and held by 4 WorldCat member libraries worldwide

Structure and dynamics of liquid helium systems and their interaction with atomic dopants and free electrons by David Mateo Valderrama( )

3 editions published in 2013 in English and held by 3 WorldCat member libraries worldwide

Magnetisme i estructura en aliatges funcionals by David González Alonso( )

3 editions published in 2014 in English and held by 3 WorldCat member libraries worldwide

Oscillatory pipe flow of wormlike micellar solutions by Laura Casanellas Vilageliu( )

3 editions published in 2013 in English and held by 3 WorldCat member libraries worldwide

L'objectiu d'aquesta Tesi és estudiar el flux oscil·latori vertical en fluids micel·lars. Els fluids micel·lars són fluids complexos amb propietats viscoelàstiques, de manera que mostren un comportament intermedi entre els sòlids i els líquids: són elàstics a escales de temps curtes però flueixen a escales de temps més llargues. En contraposició als fluids Newtonians, que tenen una viscositat constant, els fluids complexos mostren un comportament no-Newtonià, amb una viscositat que depèn del ritme de deformació. El fluxos oscil·latoris de fluids Newtonians o complexos en geometries confinades són especialment importants en fisiologia, en relació amb el sistema circulatori i respiratori d'éssers humans, i també en processos industrials com el bombejat de fluids, l'extracció de petroli, i en particular són interessants en la caracterització reològica de fluids complexos. Primer estudiem el flux oscil·latori des d'una perspectiva teòrica i analitzem el flux laminar de fluids viscoelàstics utilitzant els models de Maxwell i Oldroyd-B en un tub vertical. Hem mostrat que en fluxos confinats existeix la possibilitat que les ones de cisalla generades a les diferents parets se sobreposin abans d'esmorteir-se i que eventualment donin lloc a un fenomen de ressonància. Les prediccions teòriques obtingudes pel flux laminar són validades duent a terme experiments de Velocimetria d'Imatges de Partícules (PIV) en un tub vertical, per amplituds petites del forçament oscil·latori. Quan s'incrementa l'amplitud de l'oscil·lació el flux laminar evoluciona cap a fluxos que presenten una dependència espai-temporal més complexa. Fent rampes d'amplitud creixent a una freqüència fixada hem pogut caracteritzar experimentalment la transició del flux laminar a aquests fluxos més complexos, sota condicions de forçament ben controlades. La primera inestabilitat apareix quan el flux laminar esdevé inestable amb la corresponent formació d'anells de vorticitat apilats al llarg del tub. Es manifesta una segona inestabilitat per amplituds del forçament més grans, per la qual el flux vortical perd la simetria axial. En aquest nou règim els vòrtex estan fortament distorsionats i no són axisimètrics. Fent rampes d'amplitud creixent i decreixent hem observat que aquestes dues transicions presenten histèresi, i que per tant són de caràcter subcrític
Josephson effect in multicomponent Bose-Einstein condensates by Marina Melé Messeguer( )

3 editions published in 2013 in English and held by 3 WorldCat member libraries worldwide

En aquesta Tesi s'estudia i es caracteritza el comportament dels condensats de Bose-Einstein en una junció bosònica de Josephson (BJJ), tot utilitzant dos formalismes teòrics diferents: l'aproximació de camp mig (amb l'equació de Gross-Pitaevskii) i càlculs de molts cossos (basats en models de Bose-Hubbard). En condensats d'una sola component, ens hem centrat en l'estudi de l'estructura de l'estat fonamental en funció dels paràmetres del sistema. Hem identificat estats altament correlacionats que no es poden descriure amb teories de camp mig, i hem proposat una funció d'ona variacional que captura l'estructura de l'estat fonamental en un ampli ventall de valors d'aquests paràmetres. També hem estudiat els efectes no lineals de l'equació de Gross-Pitaevskii, visibles quan les interaccions entre àtoms són fortes. Per condensats formats per dues components hem fet un estudi intensiu dels diferents règims que es poden formar i en quines condicions. Hem utiltizat el formalisme de camp mig i hem derivat l'aproximació bimodal estàndard millorada (I2M) tot comprovant-ne la seva validesa, comparant-la amb simulacions numèriques de l'equació de Gross-Pitaevskii tridimensional. També hem estudiat condensats espinorials en una BJJ externa. Ens hem centrat en condensats formats per àtoms amb spin $F=1$, que poden estar en qualsevol dels tres estats interns $m_F=0,\pm 1$. Primer, hem estudiat aquest sistema dins la teoria de camp mig, tot utilitzant l'equació de Gross-Pitaevskii. Hem derivat les equacions de l'aproximació bimodal, i ens hem centrat en estudiar com es desacobla l'efecte Josephson de la dinàmica d'intercanvi de partícules. Segon, hem utilitzant el formalisme de Bose-Hubbard i hem caracteritzat l'estat fonamental, tot fixant-nos en els effectes de la creació de singlets. Finalment, hem estudiat l'efecte de temperatura finita en condensats de Bose-Einstein espinorials en presència d'un camp magnètic, per dos casos ben diferenciats: 1) un condensat amb $F=1$ i interaccions de contacte i 2) un condensat amb $F=3$ i interaccions de contacte i dipolars. Per a tots dos cassos, proposem un mètode per fer termometria a molt baixes temperatures, i un mètode per refredar el sistema tot variant el camp magnètic extern
Searching for P- and CP- odd effects in heavy ion collisions by Xumeu Planells Noguera( )

3 editions published in 2014 in English and held by 3 WorldCat member libraries worldwide

Separación de fases en mezclas binarias : dinámica interfacial y perturbaciones externas by Ana María Lacasta Palacio( )

2 editions published in 1994 in Spanish and held by 3 WorldCat member libraries worldwide

Model d'Ising amb camps aleatoris : propietats i aplicacions by Xavier Illa i Tortós( )

3 editions published between 2006 and 2008 in Catalan and held by 3 WorldCat member libraries worldwide

Non-mesonic weak decay of hypernuclei in effective field theory by Axel Pérez-Obiol Castañeda( )

3 editions published in 2014 in English and held by 3 WorldCat member libraries worldwide

In this thesis we have described the weak Lambda N to NN interaction, which is the main responsible for the decay of heavy hypernuclei, within the effective field theory (EFT) framework. The EFT is developed up to second order in "q", where "q" is the transferred momentum between the interacting baryons. In particular, all the two-pion exchange diagrams entering at second order in the momentum expansion have been calculated. Numerical values for the leading order low-energy constants are obtained by two means. First, a fit to the hypernuclear decay observables for three light hypernuclei, 5-Lambda/He, 11-lLambda/B i 12/Lambda/C, has been performed. This calculation has involved a proper description of the initial and final nuclear states within a many-body formalism. Second, the EFT has been compared to the one-meson-exchange model describing the same interaction. By expanding the one-meson-exchange potentials in powers of momentum, the low energy constants appearing in the EFT description have been written in terms of the heavy meson parameters. In order to obtain a less model dependent description of the weak decay of hypernuclei we have studied the decay of the lightest hypernucleus, the hypertriton, which can be described within an effective field theory framework in both the strong and the weak sectors
Colisiones de partículas cargadas modelos de interacción y algoritmos numéricos by David Bote Paz( )

3 editions published in 2010 in Spanish and held by 3 WorldCat member libraries worldwide

Applications of supersymmetry : exact results, gauge-gravity duality and condensed matter by Alejandro Barranco López( )

3 editions published in 2014 in English and held by 3 WorldCat member libraries worldwide

The study of supersymmetry has led us to a better understanding of field theories, specially in the strong coupling regime. In this thesis we have tried to show this through several examples. These are: - The first of these examples has been the application of localization techniques in supersymmetric theories. Specifically, we have used the partition function of N=2 supersymmetric Chern-Simons theory with gauge group U(N) and 2Nf flavors. To regularize the theory, it is necessary to make the computation in a three sphere whose radius, R, serves as an IR regulator which can be taken to infinity at the end of the computation. Once we have the exact partition function in terms of a matrix integral, we can solve the integral by means of a saddle-point approximation. This approximation becomes exact in the large N limit. The saddle-point equation can be solved exactly and in the decompactification limit it shows different phases depending on the value of the 't Hooft coupling. We have also computed the free energy and the vacuum expectation value of a Wilson loop for a big circle of the three sphere. Both of them show discontinuities in their derivatives, in particular, the discontinuity in the free energy appears in the third derivative and thus, both phase transitions are third order. - Other application that we have seen consists of the use of the gauge/gravity duality. In particular, starting from the gravity dual to N=1 super Yang-Mills, proposed by Maldacena and Núñez, we have reviewed how to add flavors (quarks) to this theory, without mass first and with mass later. We have also seen how to extract information about the field theory from these gravity duals, we have paid special attention to how the beta-function of the field theory dual is obtained from the gravity background proposed by Conde, Gaillard and Ramallo, dual to N=1 super Yang-Mills field theory with Nf massive flavors and a quartic superpotential. The main result from the point of view of the field theory is that, in the case Nf=2N, the beta-function shows a non-trivial UV fixed point, which hints on possible IR fixed point as proposed by Seiberg in the conformal window picture. No evidence of non-trivial fixed points is found for Nf different from 2N. - Again, in the context of the gauge/gravity duality, we have studied how to generate new supergravity solutions applying T-duality and how this affects the G-structures that describe the supersymmetry of these solutions. We have applied T-duality to the IIB supergravity solution of Klebanov and Witten with flavors. The supersymmetry of these backgrounds can be described by an SU(3)-structure and an SU(2)-structure before and after T-dualizing, respectively. - Finally, we have presented an N=1 supersymmetric model that exhibits a superconducting phase transition. This model is based on a quartic Kähler potential for a chiral multiplet and no superpotential. The main difference with standard superconductivity is that the phase transition becomes first order rather than second order. Another difference is that, as it is typical in supersymmetric theories, the dependence on the cut-off is softened in our model
Inclusive b-jet production cross section measurement at LHCb by Alessandro Camboni( )

3 editions published between 2013 and 2014 in English and held by 3 WorldCat member libraries worldwide

Semiclassical approach to relativistic nuclear mean field theory by Mario Centelles Aixalà( Book )

4 editions published between 1992 and 2009 in English and held by 3 WorldCat member libraries worldwide

On the origin of masses at the LHC by Juan González Fraile( )

3 editions published in 2014 in English and held by 3 WorldCat member libraries worldwide

 
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Audience Level
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Audience level: 0.96 (from 0.93 for Fonaments ... to 0.98 for Fonaments ...)

Alternative Names
Universitat de Barcelona. Divisió III de Ciències Experimentals i Matemàtiques. Departament d'Estructura i Constituents de la Matèria

Universitat de Barcelona. Facultat de Física. Departament d'Estructura i Constituents de la Matèria

Languages
English (31)

Catalan (20)

Spanish (5)