BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:The rigorous construction of the 1D Extended Hubbard model by RG
techniques
DTSTART;VALUE=DATE-TIME:20150609T133000Z
DTEND;VALUE=DATE-TIME:20150609T143000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-11@cern.ch
DESCRIPTION:Speakers: BENFATTO\, Giuseppe (Tor Vergata Univ.)\nDescription:
In the last twenty years\, many people in Rome have studied
various\ntypes of Fermion models\, by applying rigorous RG techniques. One
of\nthese people was Pierluigi Falco and the paper I will speak
about\,\nwritten in collaboration with Vieri Mastropietro and myself\,
was\nhis last one.\n\nThe line of research on rigorous RG was open at the
end of the 80's\nby Giovanni Gallavotti\, who published on JSP in 1990\,
in\ncollaboration with myself\, a paper on the weakly interacting
Fermi\ngas in one and three dimensions.\n\nIn this talk I will give\,
without too many technical details\, a review of the\nresults that have
been obtained in the case of the one dimensional extended\nHubbard model
(a gas of fermions of spin 1/2 on the one dimensional lattice)\nat weak
coupling and generic repulsive short range interaction.\n\nThese results
concern the existence of the zero temperature limit\nof the Grand
Canonical Ensemble\, the Borel summability of\nperturbation theory and
some universal relations satisfied by some\ncritical indices and certain
thermodynamical quantities (all\ndepending on the coupling and all other
details of the model).\nThese universal relations were conjectured many
years ago in the\nphysical literature\, but were checked only in some
special solvable\nspinless fermion models.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=11&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=11&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Renormalization Group Approach for the Optimally Doped Cuprates
DTSTART;VALUE=DATE-TIME:20150611T100000Z
DTEND;VALUE=DATE-TIME:20150611T110000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-10@cern.ch
DESCRIPTION:Speakers: FERRAZ\, Alvaro (Rio Grande do Norte Univ.
(Brazil))\nDescription: We present an overview of the field-theoretical
renormalzation group\napproach for interacting electrons in the normal
phase of the optimally\ndoped cuprates. Earlier calculations predicted the
existence of d-wave\ncharge density instabilities(d-CDW) which were later
verifed in several\nexperiments in non-Lanthanum materials. However the
onset of the so-called\npseudogap state remains an open problem to this
date. We will discuss some\nalternatives for this riddle\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=10&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=10&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Coulomb system at the KT transition\, part II
DTSTART;VALUE=DATE-TIME:20150609T100000Z
DTEND;VALUE=DATE-TIME:20150609T110000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-13@cern.ch
DESCRIPTION:Speakers: BRYDGES\, David (British Columbia Univ.
(Canada))\nDescription: In a recent paper http://arxiv.org/abs/1311.2237\,
Pierluigi Falco\nderived the detailed asymptotics of the correlation
function of the\ncritical Coulomb system in two dimensions at low
density\, as predicted\nby Berezinskii\, Kosterlitz and Thouless. In this
second of a two part\nlecture\nwe will review this result and explain some
of key ideas in this remarkable\nachievement.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=13&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=13&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Coulomb system at the KT transition\, part I
DTSTART;VALUE=DATE-TIME:20150609T090000Z
DTEND;VALUE=DATE-TIME:20150609T100000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-12@cern.ch
DESCRIPTION:Speakers: BAUERSCHMIDT\, Roland (Harvard Univ.
(USA))\nDescription: In a recent paper http://arxiv.org/abs/1311.2237\,
Pierluigi Falco\nderived the detailed asymptotics of the correlation
function of the\ncritical Coulomb system in two dimensions at low
density\, as predicted\nby Berezinskii\, Kosterlitz and Thouless. In this
first of a two part\nlecture\nwe will review this result and explain some
key ideas in this remarkable\nachievement.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=12&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=12&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anomalies and universality in statistical mechanics
DTSTART;VALUE=DATE-TIME:20150609T143000Z
DTEND;VALUE=DATE-TIME:20150609T153000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-15@cern.ch
DESCRIPTION:Speakers: Prof. MASTROPIETRO\, Vieri (Universita' di Roma Tor
Vergata)\nDescription: Around 2007 Pierluigi Falco sent me a two line mail
writing\nsomething like "then we can prove the kadanoff relation $x_-
x_+=1$". This\nwas the end of a two year discussion between we two (which
I will be\nrecall in my seminar)\n\non the renormalization/non
renormalization of the anomalies in quantum\nfield theory and its
implications for universality in statistical\nmechanics\; the complete
proof of universality relations in non solvable\nspin models was later on
published (Benfatto\, Falco\, Mastropietro CMP 292\,\n509 (2009))\, and
this opened a very exciting research line\, crowned to\n\nthe proof of
universality in the conductivity in Graphene or in the\nHubbard model.
While the combination\n\nof the properties of anomalies with constructive
Renormalization Group\nseems the right tool to understand universality in
equilibrium statistical\nphysics\, I will describe some universality
results in non equilibrium one\ndimensional interacting fermions which
apparently do not fit in this\nscheme.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=15&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=15&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Large deviations for singular stochastic partial differential
equations
DTSTART;VALUE=DATE-TIME:20150610T133000Z
DTEND;VALUE=DATE-TIME:20150610T143000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-14@cern.ch
DESCRIPTION:Speakers: JONA LASINIO\, Giovanni (ROMA1)\nDescription: We
consider SPDE's whose solutions are distribution-valued fields.
An\nexample is provided by the stochastic quantization of a scalar field
in\nd=2\,3 where infinite counter-terms are necessary. We review
large\ndeviation estimates for probabilistic weak solutions in d=2\,
derived long ago\nwith P. K. Mitter\, which show that the rate functional
does not depend on the\nrenormalization counter terms. We shall compare
this result with a similar\nconclusion reached recently by Hairer and
Weber in the context of\nHairer regularity structures\, which cover also
the d=3 case.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=14&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=14&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Results and conjectures about the XY model
DTSTART;VALUE=DATE-TIME:20150609T073000Z
DTEND;VALUE=DATE-TIME:20150609T083000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-17@cern.ch
DESCRIPTION:Speakers: SPENCER\, Thomas (IAS (USA))\nDescription: In this
review talk I will explain how Falco's work on the Coulomb gas is\nrelated
to the 2D XY model at T_c. In 3D I will present some open problems\nat
low temperature\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=17&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=17&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Singular Stochastic PDEs and Dynamical Field Theory Models
DTSTART;VALUE=DATE-TIME:20150610T123000Z
DTEND;VALUE=DATE-TIME:20150610T133000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-16@cern.ch
DESCRIPTION:Speakers: MITTER\, Pronob K. (Montpellier Univ.
(France))\nDescription: There is considerable interest at present in
Singular\nStochastic PDEs especially\nin connection with Rough Path Theory
in different guises. The mathematical\nwork started with results by
Gianni Jona-Lasinio\nand myself a long time ago. I will review what was
was accomplished at\nthe time and the progress that\nhas been made since
then. One reason for presenting this to this audience\nis that there is\,
in my opinion\, considerable scope\nfor rigorous renormalisation group
work in this subject. I will also\nattempt to prepare the ground for
Gianni’s talk to follow\non large deviations for singular SPDEs.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=16&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=16&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Probabilistic method in combinatorics using cluster expansion
DTSTART;VALUE=DATE-TIME:20150610T143000Z
DTEND;VALUE=DATE-TIME:20150610T153000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-19@cern.ch
DESCRIPTION:Speakers: SCOPPOLA\, Benedetto (Univ. Tor Vergata
Roma)\nDescription: We will discuss the connection between the cluster
expansion\nand the probabilistic method\, used in order\nto give a-priori
bounds for discrete combinatorics problems.\nAccurate estimates of the
radius of convergence of the cluster\nexpansion\, as the Fernandez-
Procacci construction\, allow better\nestimates in the related
combinatorics\nproblems. We provide concrete examples of applications of
this\ntechnique.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=19&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=19&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Proof of a 43-year-old prediction by Wilson on anomalous scaling
for a hierarchical composite field
DTSTART;VALUE=DATE-TIME:20150611T090000Z
DTEND;VALUE=DATE-TIME:20150611T100000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-20@cern.ch
DESCRIPTION:Speakers: ABDESSELAM\, Abdelmalek (Virginia Univ.
(USA))\nDescription: Hierarchical models a.k.a. the approximate recursion
played a\nfundamental role in the discovery\nof the epsilon-expansion for
critical exponents by Wilson and Fisher. In\na not so well known 1972
article\,\nWilson showed\, at the heuristic level\, that at a nontrivial
hierarchical\nmodel fixed point\, the elementary field\nhas no anomalous
scaling whereas the composite square field does have\none. I will report
on a joint work with Ajay Chandra and Gianluca\nGuadagni on a particular
hierarchical model\, the p-adic model\, which\nrigorously proves Wilson's
prediction. The two main ideas are a\nconstructive renormalization group
for space dependent couplings and a\nholomorphic partial linearization
theorem in infinite dimension\, in the\nspirit of Wegner's theory of
nonlinear scaling fields. I will also\nreport on recent progress I am
making in the analysis of short distance\nbehavior such as the pointwise
representability of correlation\nfunctions. The goal is to prove the
operator product expansion and\ngeneralize the pathwise construction of
squares of random distributions\ngiven by Wick powers to the setting of a
nontrivial fixed point with\nanomalous dimensions.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=20&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=20&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Validity of Spin Wave Approximation for the Quantum Heisenberg
Ferromagnet
DTSTART;VALUE=DATE-TIME:20150611T123000Z
DTEND;VALUE=DATE-TIME:20150611T133000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-1@cern.ch
DESCRIPTION:Speakers: Dr. CORREGGI\, Michele (Roma Tre
University)\nDescription: We consider the quantum ferromagnetic Heisenberg
model in three dimensions\, for all spins $ S \\geq \\frac{1}{2} $. We
report on a rigorous proof of the validity of the spin-wave approximation
for the excitation spectrum\, at the level of the first non-trivial
contribution\nto the free energy at low temperatures. Our proof comes with
explicit\,\nconstructive upper and lower bounds on the error term. Such
estimates are obtained combining the bosonic Holstein-Primakoff
representation of the Heisenberg model with localization bounds and
operator inequalities.\nJoint work with A. Giuliani (Roma 3) and R.
Seiringer (IST Austria).\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=1&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=1&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Renormalization group\, Kondo effect and hierarchical models
DTSTART;VALUE=DATE-TIME:20150609T123000Z
DTEND;VALUE=DATE-TIME:20150609T133000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-0@cern.ch
DESCRIPTION:Speakers: GALLAVOTTI\, Giovanni (ROMA1)\nDescription: A
manifestation of the Kondo effect is the non divergence at
zero\ntemperature\nof the susceptibility of an impurity magnetization to
the action of a\nfield. It is a quantum phenomenon not accessible to
perturbation theory\nbecause it is essential that the interaction with the
host lattice\nelectrons is antiferromagnetic\, no matter how small. Its
theory in one\ndimension\, due to Wilson\, is based on the renormalization
group and its\ninterest is that it has been one the first and few cases
in which a\nmultiscale phenomenon controlled by a non trivial fixed point
as been\nunderstood.\nWilson's approach has not been based on functional
integration: here I\nshall discuss\na hierarchical model for a system
exhibiting the Kondo effect: its nine\nrunning couplings (of which $2$ are
relevant $4$ are marginal and $3$\nirrelevant) flow under a beta function
which can be computed exactly and\nwhich generates a flow with several
properties which give a picture of the\nphenomenon.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=0&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=0&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Limit Theorems in Quantum Theory
DTSTART;VALUE=DATE-TIME:20150610T073000Z
DTEND;VALUE=DATE-TIME:20150610T083000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-2@cern.ch
DESCRIPTION:Speakers: Prof. FROEHLICH\, Juerg (ETH Zurich)\nDescription: I
present an outline of the theory of information acquisition in quantum
mechanics. I discuss some relevant mathematical techniques from functional
analysis and probability theory needed to develop this theory. In order
to keep the presentation down to earth\, I focus on the discussion of
concrete examples of indirect and non-demolition measurements.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=2&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=2&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Height Fluctuations in Interacting Dimers
DTSTART;VALUE=DATE-TIME:20150610T100000Z
DTEND;VALUE=DATE-TIME:20150610T110000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-4@cern.ch
DESCRIPTION:Speakers: Prof. GIULIANI\, Alessandro (Univ. Roma
Tre)\nDescription: Perfect matchings of Z^2 (also known as non-interacting
dimers on the\nsquare lattice) are an exactly solvable 2D statistical
mechanics model. It\nis known that the associated height function behaves
at large distances\nlike a massless gaussian field\, with the variance of
height gradients\ngrowing logarithmically with the distance. As soon as
dimers mutually\ninteract\, via e.g. a local energy function favoring the
alignment among\nneighboring dimers\, the model is not solvable anymore
and the dimer-dimer\ncorrelation functions decay polynomially at infinity
with a non-universal\n(interaction-dependent) critical exponent. We prove
that\, nevertheless\,\nthe height fluctuations remain gaussian even in the
presence of\ninteractions\, in the sense that all their moments converge
to the gaussian\nones at large distances. The proof is based on extension
of the\nInteracting Fermions Picture method\, proposed and employed by P.
Falco in\nthe study of the universality of critical exponents in the
interacting\ndimer model. An important novelty of our approach is the
combination of\nmultiscale methods with the path-independence properties
of the height\nfunction.\nJoint work with V. Mastropietro and F.
Toninelli.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=4&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=4&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Universality of conductivity in interacting graphene
DTSTART;VALUE=DATE-TIME:20150610T090000Z
DTEND;VALUE=DATE-TIME:20150610T100000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-7@cern.ch
DESCRIPTION:Speakers: PORTA\, Marcello (Zurich Univ.)\nDescription:
Graphene is a recently discovered material\, which can be\nconsidered as
the first realization of a two-dimensional crystal. Its\nunique physical
properties elicited great interest in the condensed matter\nphysics
community\, both from a theoretical and an experimental point
of\nview.\nRemarkably\, some interesting features of graphene can be
understood from a\nmathematically rigorous viewpoint. In this talk\, I
will consider the\nHubbard model on the honeycomb lattice at half-
filling\, as a model for\nundoped graphene in the presence of short-range
interactions. I will\npresent a rigorous proof of the universality of the
optical conductivity\,\nwhich agrees with recent experiments: the
conductivity has a universal\nvalue\, which does not depend on the
microscopic details of the model. In\nparticular\, there are no
interaction corrections\, provided that the\ninteraction is weak enough.
Also\, I will report about recent progress in\nthe understanding of the
universality of the Hall conductivity in a related\nmodel\, the
interacting Haldane model. The results are based on a
rigorous\nformulation of the Wilsonian renormalization group and on Ward
identities.\nThis is joint work with A. Giuliani and V.
Mastropietro.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=7&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=7&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quantum Phase Transition in an Interacting Fermionic Chain
DTSTART;VALUE=DATE-TIME:20150611T133000Z
DTEND;VALUE=DATE-TIME:20150611T143000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-9@cern.ch
DESCRIPTION:Speakers: BONETTO\, Federico (Georgia Tech -
Atlanta)\nDescription: We rigorously analyze the quantum phase transition
between a\nmetallic and an\ninsulating phase in (non solvable)
interacting spin chains or one\ndimensional\nfermionic systems. In
particular\, we prove the persistence of Luttinger\nliquid behavior in the
presence of an interaction even arbitrarily close to\nthe critical
point\, where the Fermi velocity vanishes and the two Fermi\npoints
coalesce. The\nanalysis is based on two different multiscale analysis\;
the analysis of\nthe first regime provides gain factors which compensate
exactly the small\ndivisors due to the vanishing Fermi velocity. This is a
joint work with\nVieri Mastropietro.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=9&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=9&confId=9369
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anomaly cancellation to all orders in chiral abelian gauge
theories - A peturbative analysis based on (Bi)flow equations -
DTSTART;VALUE=DATE-TIME:20150611T073000Z
DTEND;VALUE=DATE-TIME:20150611T083000Z
DTSTAMP;VALUE=DATE-TIME:20170923T124024Z
UID:indico-contribution-9369-8@cern.ch
DESCRIPTION:Speakers: KOPPER\, Christoph (Ecole Polytechnique
Palaiseau)\nDescription: We prove that the cancellation of the chiral
anomaly\nin four-dimensional axial QED\, as a consequence of a\nsum rule
on the fermion charges\, is valid to all\norders in perturbation theory.
The proof is based on\nanalysing separately the fermionic and
bosonic\nrenormalization group flows.\nURL:
https://agenda.infn.it/contributionDisplay.py?contribId=8&confId=9369
LOCATION:INFN - Laboratori Nazionali di Frascati
Auditorium B. Touschek\, Bldg 36
URL:https://agenda.infn.it/contributionDisplay.py?contribId=8&confId=9369
END:VEVENT
END:VCALENDAR