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BEGIN:VEVENT
SUMMARY:Tensor renormalization group approach to higher dimensional fermio
ns
DTSTART;VALUE=DATE-TIME:20160726T171000Z
DTEND;VALUE=DATE-TIME:20160726T173000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2334@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Ryo Sakai (Kanazawa University)\nWe apply the higher
order tensor renormalization group to two and three dimensional lattice f
ermion systems. To deal with the tensor network including Grassmann number
s\, higher order Grassmann tensor renormalization group (HOGTRG) is introd
uced. Because of its deterministic property\, HOGTRG is perfectly free of
the sign problem. We analyze the well-known systems such as the Gross–Ne
veu model using HOGTRG\, and test the validity of the new algorithm.\n\nht
tps://conference.ippp.dur.ac.uk/event/470/contributions/2334/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2334/
END:VEVENT
BEGIN:VEVENT
SUMMARY:How to make a quantum black hole with ultra-cold gases
DTSTART;VALUE=DATE-TIME:20160725T172500Z
DTEND;VALUE=DATE-TIME:20160725T174500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2345@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Masanori Hanada (Kyoto U\, Stanford U)\nWe argue tha
t a small\, quantum black hole can be made from atoms and lasers.\n\nThe h
olographic principle claims that the quantum gravitational systems\, e.g.
superstring theory\, is equivalent to non-gravitational quantum systems\,
e\,g. super Yang-Mills theory. Here the 'equivalence' means two theories c
annot be distinguished even in principle. Therefore\, if the holographic p
rinciple is true\, then by engineering the non-gravitational systems by us
ing an optical lattice\, one can create actual quantum black holes.\n\nIn
this presentation\, we consider the simplest example: the Sachdev-Ye-Kitae
v (SYK) model.\nWe design a an experimental scheme for creating the SYK mo
del with use of ultra-cold fermionic atoms. \n\nThis presentation is based
on a paper "Creating and probing the Sachdev-Ye-Kitaev model with ultraco
ld gases: Towards experimental studies of quantum gravity\," arXiv:1606.02
454 with Ippei Danshita (Yukawa Institute for Theoretical Physics\, Kyoto
University) and Masaki Tezuka (Deptartment of Physics\, Kyoto University).
\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2345/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2345/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Search for a continuum limit of the PMS phase
DTSTART;VALUE=DATE-TIME:20160726T165000Z
DTEND;VALUE=DATE-TIME:20160726T171000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2348@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Venkitesh Ayyar (Duke University)\nPrevious studies
of a simple four-fermion model with staggered fermions in 3d have shown th
e existence of an exotic quantum critical point\, where one may be able to
define a continuum limit of the Paramagnetic Strong Phase (or the PMS pha
se). We believe the existence of the critical point suggests a new mechani
sm for generating fermion masses. In this work we begin the search for thi
s quantum critical point in 4d by extending the 3d model to 4d.\nUnlike in
3d\, now we do find evidence for an intermediate spontaneously broken pha
se (FM phase) and are able compute the phase boundaries accurately. In ter
ms of the bare coupling\, the width of the intermediate region appears to
be quite small.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributi
ons/2348/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2348/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Slab Method to Measure the Topological Susceptibility
DTSTART;VALUE=DATE-TIME:20160725T131500Z
DTEND;VALUE=DATE-TIME:20160725T133500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2366@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Wolfgang Bietenholz (UNAM\, Mexico)\nIn simulations
of a model with topological sectors\,\nalgorithms which proceed in small u
pdate steps\ntend to get stuck in one sector\, especially on fine \nlattic
es. This distorts the numerical results\; in \nparticular it is not straig
htforward to measure the \ntopological susceptibility chi_t.\nHere we test
a method to measure chi_t even if configurations \nfrom only one sector a
re available. It is based on the topological\ncharges in sub-volumes\, whi
ch we denote as ''slabs''. Under\nsuitable circumstances\, this enables th
e evaluation of chi_t\,\nas we demonstrate with numerical data for non-lin
ear sigma-models\nand 2-flavor QCD.\n\nhttps://conference.ippp.dur.ac.uk/e
vent/470/contributions/2366/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2366/
END:VEVENT
BEGIN:VEVENT
SUMMARY:$B\\to K^*$ decays in a finite volume
DTSTART;VALUE=DATE-TIME:20160726T130000Z
DTEND;VALUE=DATE-TIME:20160726T132000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2376@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Akaki Rusetski (HISKP\, University of Bonn\, Germany
)\nWe propose a framework for the extraction of the $B\\to K^*$ decay form
factors from lattice data\, based on the non-relativistic effective field
theory in a finite volume. A possible admixture of the $\\eta K$ channel
is studied\, and the multi-channel Lellouch-Luescher formula is reproduced
. Further\, a procedure is\nformulated for the extraction of the form-fact
ors at the resonance pole. The definition of the photon virtuality at the
resonance pole is discussed. The limit of an infinitely narrow resonance i
s investigated in detail in the multi-channel case.\n\nhttps://conference.
ippp.dur.ac.uk/event/470/contributions/2376/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2376/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Borici-Creutz fermions on 2-dim lattice
DTSTART;VALUE=DATE-TIME:20160726T161000Z
DTEND;VALUE=DATE-TIME:20160726T163000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2389@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Jishnu Goswami (IIT Kanpur)\nMinimally doubled fermi
ons(MDF) having only two species could be\npromising formalism to study ch
iral fermion on a lattice. The action being ultra-local\, one expects that
the MDF formulations might provide computationally cheaper\nalternatives
to the existing lattice chiral formulations. Borici-Creutz fermion is one
such\nminimally doubled fermion formulation. In this work\, we explore th
e Borici-Creutz fermion\nformulation in simple a 2d Gross-Neveu model and
in QED2 with Hybrid Monte Carlo simulation. We study chiral symmetry break
ing and mass spectrum in Gross-Neveu model .\n\nhttps://conference.ippp.d
ur.ac.uk/event/470/contributions/2389/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2389/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Meson masses and decay constants at large N
DTSTART;VALUE=DATE-TIME:20160727T105000Z
DTEND;VALUE=DATE-TIME:20160727T111000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2394@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Masanori Okawa (Hiroshima University)\nMeson masses
and decay constants in the large N limit of SU(N) gauge theory is estimate
d from the twisted space-time reduced model. To this end\, we introduce a
new smearing method which enables us to obtain reliable values for these
quantities.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2
394/
LOCATION:Highfield Campus\, University of Southampton Building B2a Room 20
77
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2394/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sea quark QED effects and twisted mass fermions
DTSTART;VALUE=DATE-TIME:20160726T163000Z
DTEND;VALUE=DATE-TIME:20160726T165000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2397@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Roberto Frezzotti (University of Rome Tor Vergata\,
Physics Department and INFN - Sezione di Roma Tor Vergata)\nWe show that m
aximally twisted mass fermions can be employed to regularize on the lattic
e\nthe fully unquenched QCD+QED theory with vanishing theta-term. We discu
ss how the critical\nmass of the up and down quarks can be conveniently de
termined beyond the electroquenched\napproximation by imposing that certai
n symmetries of continuum QCD+QED\, which are broken by\nWilson terms\, ar
e restored (up to cutoff effects). A mixed action setup is sketched that a
llows to extend the computation of the leading isospin breaking correction
s to physical observables via the RM123 method beyond the electroquenched
approximation by using ETMC (pure QCD) gauge configurations with N_f=2+1+1
dynamical quark flavours\, with only O(a^2) lattice artifacts.\n\nhttps:/
/conference.ippp.dur.ac.uk/event/470/contributions/2397/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2397/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The gradient flow coupling from numerical stochastic perturbation
theory
DTSTART;VALUE=DATE-TIME:20160727T084000Z
DTEND;VALUE=DATE-TIME:20160727T090000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2408@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Mattia Dalla Brida (DESY - Zeuthen)\nThe perturbativ
e calculation of gradient flow observables is technically challenging. \nC
urrent results are in fact limited to a few quantities and\, in general\,
to low perturbative orders. Numerical stochastic perturbation theory is a
potentially powerful tool that may be applied in this context. Precise res
ults using these techniques\, however\, require control over both statisti
cal and systematic uncertainties. In this talk we discuss how the recent a
lgorithmic developments of these methods substantially ameliorate the cost
for such precise computations. As an illustration we then present results
for the two-loop matching of the gradient flow coupling in finite volume
with Schroedinger functional boundary conditions and the $\\overline{\\rm
MS}$ coupling.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contribution
s/2408/
LOCATION:Highfield Campus\, University of Southampton Building B2a Room 20
77
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2408/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Renormalisation of the scalar energy-momentum tensor with the Wils
on flow
DTSTART;VALUE=DATE-TIME:20160727T080000Z
DTEND;VALUE=DATE-TIME:20160727T082000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2453@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Susanne Ehret (University of Edinburgh)\nThe Wilson
flow is a promising tool to study strongly coupled theories. Its remarkabl
e renormalisation properties allow for a meaningful formulation of the ene
rgy-momentum tensor on the lattice. The non-perturbative computation of th
e latter can in turn be used to study the scaling behaviour of quantum fie
ld theories. We extent recent studies on the renormalisation of the energy
-momentum tensor in 4-dimensional gauge theory to the case of a 3-dimensio
nal scalar theory to investigate its intrinsic structure and numerical fea
sibility on a more basic level. In this talk\, we introduce the Wilson flo
w for scalar theory\, discuss Ward identities\, and present our results fo
r the renormalisation constants of the scalar energy-momentum tensor.\n\nh
ttps://conference.ippp.dur.ac.uk/event/470/contributions/2453/
LOCATION:Highfield Campus\, University of Southampton Building B2a Room 20
77
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2453/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fermion bags\, topology and index theorems
DTSTART;VALUE=DATE-TIME:20160725T135500Z
DTEND;VALUE=DATE-TIME:20160725T141500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2468@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Shailesh Chandrasekharan (Duke University)\nIn this
talk we argue that the fermion bag formulation extends the concepts of top
ology and index theorems associated with non-Abelian gauge theories\, to s
imple lattice fermion field theories. Through such a connection we learn t
hat fermion masses can arise in at least two different ways:(1) a conventi
onal way where some lattice symmetry of the action is spontaneously\, expl
icitly or anomalously broken and (2) an unconventional way where all latti
ce symmetries are preserved. We argue for these two scenarios by consideri
ng simple examples of lattice field theories formulated with staggered fer
mions.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2468/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2468/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tensor RG calculations and quantum simulations near criticality
DTSTART;VALUE=DATE-TIME:20160726T144000Z
DTEND;VALUE=DATE-TIME:20160726T150000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2485@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Yannick Meurice (University of Iowa)\nWe reformulate
the Ising model\, the O(2) model with a chemical potential and the Abelia
n Higgs model on a 1+1 space-time lattice using the \nTensor Renormalizati
on Group (TRG) method. The reformulation allows exact blocking and connect
s smoothly the classical Lagrangian approach to the quantum Hamiltonian ap
proach. We discuss the linearization of the TRG for the Ising model near t
he critical point. \nWe calculate the entanglement entropy in the superflu
id phase of the O(2) model and show that it obeys the Cardy scaling (c/3)
*Ln(L).\nWe calculate the Polyakov loop in the Abelian Higgs model and dis
cuss the possibility of a deconfinement transition at finite volume. \nWe
propose Bose-Hubbard Hamiltonians with two species implementable on optica
l lattices as quantum simulators.\n\nhttps://conference.ippp.dur.ac.uk/eve
nt/470/contributions/2485/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2485/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lattice Conformal Field theory on Curved Manifolds
DTSTART;VALUE=DATE-TIME:20160727T092000Z
DTEND;VALUE=DATE-TIME:20160727T094000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2491@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Richard Richard Brower (Boston University)\nA Quantu
m Finite Element (QFE) Lagrangian is formulated for\na general simplicial
complex approximation to a smooth Euclidean\nRiemann manifold. The constru
ction is applied to Wilson Dirac fermions\nwith the appropriate lattice sp
in connection and to phi 4th-theory\nwith QFE counter terms required for t
hese theories to converge in the\ncontinuum limit. Numerical tests are giv
en for the Wilson-Fisher\nfixed point in 2D with comparison to the exact s
olution of the Ising CFT on\nthe two sphere and for the 3D phi 4th-theory
in radial quantization.\nPotential future applications to more general 3D
conformal field theories and 4D\nBeyond the Standard Model (BSM) gauge the
ories near the conformal window are\nsuggested.\n\nhttps://conference.ippp
.dur.ac.uk/event/470/contributions/2491/
LOCATION:Highfield Campus\, University of Southampton Building B2a Room 20
77
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2491/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lattice QCD simulation of the Berry curvature
DTSTART;VALUE=DATE-TIME:20160725T145500Z
DTEND;VALUE=DATE-TIME:20160725T151500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2544@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Arata Yamamoto (University of Tokyo)\nThe Berry curv
ature is a fundamental concept describing topological order of quantum sys
tems.\nWhile it can be analytically tractable in non-interacting systems\,
numerical simulations are necessary in interacting systems.\nWe present a
formulation to calculate the Berry curvature in lattice QCD.\n\nhttps://c
onference.ippp.dur.ac.uk/event/470/contributions/2544/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2544/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Retrieving the optical potential from a Lattice simulation.
DTSTART;VALUE=DATE-TIME:20160726T132000Z
DTEND;VALUE=DATE-TIME:20160726T134000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2511@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Maxim Mai (George Washington University)\nWe propose
a method for the direct extraction of the complex hadron-hadron optical p
otential (or\, equivalently\, the phase shift and inelasticity in a given
channel) on the lattice\, which does not require the use of the multi-chan
nel Lüscher formalism\, but the knowledge of a tower of energy levels onl
y.\n\nThe approach works for any multi-particle states and tested explicit
ly on a set of synthetic data for the $\\pi\\eta-K\\bar K$ system. Further
\, we show how a sufficiently large number of energy eigenvalues can be ob
tained utilizing partial twisting.\n\nhttps://conference.ippp.dur.ac.uk/ev
ent/470/contributions/2511/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2511/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Determination of topological charge following several definitions
DTSTART;VALUE=DATE-TIME:20160725T133500Z
DTEND;VALUE=DATE-TIME:20160725T135500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2552@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Julien Frison (KEK Theory Center)\nOn the lattice\,
many definitions of the topological charge $Q$ coexist\, and can give very
different numbers on a given configuration. \nThose definitions will only
converge when one takes the continuum limit of the moments $\\langle Q^n\
\rangle$ (provided that $Q$ has been correctly renormalised). \nAdditional
ly\, other complications arise when one wants to study the mass dependence
of the topological susceptibility\, because of the mixing of the two oper
ators under renormalisation. It is therefore unclear to which extent each
definition of $Q$ is compatible with each definition of the masses. \nHere
we will present the results of some tests following various choices of de
finition. In a second part\, we will discuss the potential consequences of
that ambiguity on the discarding of $m_u=0$ as a solution to the strong $
CP$ problem.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/
2552/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2552/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A variational method for spectral functions
DTSTART;VALUE=DATE-TIME:20160726T134000Z
DTEND;VALUE=DATE-TIME:20160726T140000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2560@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Daniel Robaina (Institute for Nuclear Physics Mainz)
\nThe Generalized Eigenvalue Problem (GEVP) has been intensively used in t
he past in order to reliably extract energy levels from time-dependent euc
lidean correlators calculated in Lattice QCD. We propose an alternative fo
rmulation of the GEVP in frequency space. Our approach consists in applyin
g the model independent Backus-Gilbert method to a set of euclidean two-po
int functions with common quantum numbers. A GEVP analysis in frequency sp
ace is then applied to a matrix of estimators that allows us\, among other
things\, to obtain particular linear combinations of the initial set of o
perators that optimally overlap to different local regions in frequency. T
his approach can be interesting both for vacuum physics as well as for fin
ite temperature problems.\n\nhttps://conference.ippp.dur.ac.uk/event/470/c
ontributions/2560/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2560/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Continuing the Saga of Fluffy Mirror Fermions
DTSTART;VALUE=DATE-TIME:20160727T090000Z
DTEND;VALUE=DATE-TIME:20160727T092000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2574@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Dorota Grabowska (INT/UW)\nI discuss continuing work
on a recent proposal for the nonperturbative regulator for chiral gauge t
heories which combines domain wall fermions and gradient flow\, Phys.Rev.
Lett. 116 (2016) 211602. Implementing chiral gauge theories on the lattice
requires not only decoupling mirror fermions to allow for fermions in com
plex representations\, but also a road to failure for theories with fermio
ns in anomalous representations. Unlike attempts to gap the mirror fermion
spectrum\, this proposal gives the mirror fermions exponentially soft for
m factors\, allowing them to decouple from ordinary matter except through
nontrivial gauge field topology. I discuss progress on various open questi
ons for this formulation that were left unresolved in the original work.\n
\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2574/
LOCATION:Highfield Campus\, University of Southampton Building B2a Room 20
77
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2574/
END:VEVENT
BEGIN:VEVENT
SUMMARY:O(3) model with Nienhuis action
DTSTART;VALUE=DATE-TIME:20160726T142000Z
DTEND;VALUE=DATE-TIME:20160726T144000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2596@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Ulli Wolff (HU Berlin)\nWe study the O(3) sigma mode
l on a D=2 lattice with a Boltzmann weight linearized in $\\beta$ on each
link. \nWhile the spin formulation now suffers from a sign-problem the equ
ivalent loop model remains positive and \nbecomes particularly simple. By
studying the transfer matrix and by performing MC simulations in the loop
form \nwe study the mass gap coupling in a step scaling analysis. The ques
tion addressed is\, whether or not such a \nsimplified action still has th
e right universal continuum limit. If the answer is affirmative this would
be \nhelpful in widening the applicability of worm algorithm methods.\n\n
https://conference.ippp.dur.ac.uk/event/470/contributions/2596/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2596/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Renormalization constants of the lattice energy momentum tensor us
ing the gradient flow
DTSTART;VALUE=DATE-TIME:20160727T082000Z
DTEND;VALUE=DATE-TIME:20160727T084000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2597@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Francesco Capponi (Plymouth University)\nWe present
an update about our program for the non perturbative renormalization of th
e energy momentum tensor. Our strategy consists in probing suitable lattic
e Ward identities with observables computed along the gradient flow. This
set of identities exhibits many interesting qualities\, arising from the U
V finiteness of flowed composite operators\, and can be used to measure th
e renormalization constants of the energy momentum tensor. We show how thi
s method is applied in a SU(3) Yang-Mills theory on the lattice\, and repo
rt our numerical results.\n\nhttps://conference.ippp.dur.ac.uk/event/470/c
ontributions/2597/
LOCATION:Highfield Campus\, University of Southampton Building B2a Room 20
77
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2597/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Volume reduction through perturbative Wilson loops
DTSTART;VALUE=DATE-TIME:20160727T103000Z
DTEND;VALUE=DATE-TIME:20160727T105000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2626@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Margarita Garcia-Perez (Instituto de Fisica Teorica
UAM-CSIC)\nWe derive the perturbative expansion of Wilson loops to order g
^4 in a SU(N) lattice gauge theory with twisted boundary conditions. Our e
xpressions show that the thermodynamic limit is attained at infinite N for
any number of lattice sites and allow to quantify the deviations from vol
ume independence at finite large N as a function of the twist. The effect
of adjoint Wilson fermions will be briefly described.\n\nhttps://conferenc
e.ippp.dur.ac.uk/event/470/contributions/2626/
LOCATION:Highfield Campus\, University of Southampton Building B2a Room 20
77
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2626/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Applying recursive numerical integration techniques for solving hi
gh dimensional integrals
DTSTART;VALUE=DATE-TIME:20160726T140000Z
DTEND;VALUE=DATE-TIME:20160726T142000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2643@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Julia Volmer (DESY Zeuthen)\nThe error scaling for M
arkov Chain - Monte Carlo techniques (MC-MC)\nwith $N$ samples behaves lik
e $\\frac{1}{\\sqrt{N}}$. This scaling makes\nit often very time intensive
to reduce the error of calculated\nobservables\, in particular for applic
ations in lattice QCD. \nIt is therefore highly desirable to have alternat
ive methods at hand\nwhich show an improved error scaling. One candidate f
or such an\nalternative integration technique is the method of recursive n
umerical\nintegration (RNI). The basic idea of this method is to use Gauss
quadrature with Legendre polynomials and apply it iteratively to integrat
e over observable and\nBoltzmann weight. \nIn this talk we will present th
e application of such an algorithm to\nthe topological rotor and the anhar
monic oscillator and compare the\nerror scaling to MC-MC results. In parti
cular\, we demonstrate that the\nRNI technique shows an error scaling in $
N$ that is at least\nexponential.\n\nhttps://conference.ippp.dur.ac.uk/eve
nt/470/contributions/2643/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2643/
END:VEVENT
BEGIN:VEVENT
SUMMARY:New polynomially exact integration rules on U(N) and SU(N)
DTSTART;VALUE=DATE-TIME:20160725T170500Z
DTEND;VALUE=DATE-TIME:20160725T172500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2644@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Tobias Hartung (King's College London)\nIn lattice Q
FT\, we are often presented with integrals over polynomials of coefficient
s of matrices in $U(N)$ or $SU(N)$ with respect to the Haar measure. In so
me physical situations\, e.g.\, in presence of a chemical potential\, thes
e integrals are\, however\, numerically very difficult since they are high
ly oscillatory which manifests itself in form of the sign problem. In thes
e cases\, Monte Carlo methods often fail to be adequate\, rendering such c
omputations practically impossible.\n\nIn this talk\, we will propose a ne
w class of polynomially exact integration rules on $U(N)$ and $SU(N)$ whic
h are derived from polynomially exact rules on spheres. We will examine th
ese quadrature rules and their efficiency at the example of a $0+1$ dimens
ional QCD for a non-zero quark mass and chemical potential. In particular\
, we will demonstrate the failure of Monte Carlo methods in such applicati
ons but that we can obtain arbitrary precision results using the new polyn
omially exact integration rules.\n\nhttps://conference.ippp.dur.ac.uk/even
t/470/contributions/2644/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2644/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lattice QCD on non-orientable manifolds - part II
DTSTART;VALUE=DATE-TIME:20160725T143500Z
DTEND;VALUE=DATE-TIME:20160725T145500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2648@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Balint Toth (Bergische Universität Wuppertal)\nA co
mmon problem in lattice QCD simulations on the torus is the extremely long
autocorrelation time of the topological charge\, when one approaches the
continuum limit. The reason is the suppressed tunneling between topologica
l sectors. The problem can be addressed by replacing the torus with a diff
erent manifold. Here we propose to use a non-orientable manifold\, and sho
w how to define and simulate lattice QCD on it. Part II focuses on special
issues like the implementation of fermions on a non-orientable manifold.\
n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2648/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2648/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The multi-flavor Schwinger model with chemical potential - Overco
ming the sign problem with Matrix Product States
DTSTART;VALUE=DATE-TIME:20160725T162500Z
DTEND;VALUE=DATE-TIME:20160725T164500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2665@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Stefan Kühn (Max Planck Institute of Quantum Optics
)\nDuring recent years there has been quite some interest in applying Matr
ix Product States and more general tensor networks to lattice gauge theori
es in the Hamiltonian formulation. Previous work already demonstrated the
power of this approach by computing the mass spectrum and thermal sates fo
r the Schwinger model\, and also real-time dynamics for abelian and non-ab
elian gauge models have been successfully addressed in the meantime.\n\nIn
this talk we present ground state calculations for the two-flavor Schwing
er model with finite chemical potential using Matrix Product States. While
the conventional Monte Carlo approach suffers from the sign problem\, our
numerical simulations with Matrix Product States reliably reproduce analy
tic results for the massless case by Narayanan [Phys. Rev. D 86\, 125008 (
2012)] and readily extend to the massive case\, where no analytic predicti
on is available.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributi
ons/2665/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2665/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Phase structure analysis of CP(N-1) model using Tensor renormaliza
tion group
DTSTART;VALUE=DATE-TIME:20160725T160500Z
DTEND;VALUE=DATE-TIME:20160725T162500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2672@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Hikaru Kawauchi (Kanazawa University)\nWe investigat
e the phase structure of the lattice CP(N-1) model in two dimensions by us
ing the tensor renormalization group (TRG) method. The TRG method has no s
ign problem even though the action is complex. We focus on the case N=2 an
d compare the numerical result of the TRG method with that of the strong-c
oupling analysis in the presence of the theta term.\n\nhttps://conference.
ippp.dur.ac.uk/event/470/contributions/2672/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2672/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lattice QCD on non-orientable manifolds - part I
DTSTART;VALUE=DATE-TIME:20160725T141500Z
DTEND;VALUE=DATE-TIME:20160725T143500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2680@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Simon Mages (Forschungszentrum Jülich)\nA common pr
oblem in lattice QCD simulations on the torus is the extremely long autoco
rrelation time of the topological charge\, when one approaches the continu
um limit. The reason is the suppressed tunneling between topological secto
rs. The problem can be addressed by replacing the torus with a different m
anifold. Here we propose to use a non-orientable manifold\, and show how t
o define and simulate lattice QCD on it. Part I focuses on the motivation
and general introduction of our construction.\n\nhttps://conference.ippp.d
ur.ac.uk/event/470/contributions/2680/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2680/
END:VEVENT
BEGIN:VEVENT
SUMMARY:'t Hooft model on the lattice
DTSTART;VALUE=DATE-TIME:20160727T111000Z
DTEND;VALUE=DATE-TIME:20160727T113000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2684@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Antonio Gonzalez-Arroyo (Instituto de Fisica Teorica
UAM/CSIC)\nWe use a recently formulated expression for computing meson ma
sses at\nlarge N to study the spectrum of two-dimensional QCD in the large
N\nlimit. The model serves as a testing ground to explore methodology\nof
meson mass determination with different techniques and versions\nof latti
ce fermions.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/
2684/
LOCATION:Highfield Campus\, University of Southampton Building B2a Room 20
77
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2684/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Six-dimensional regularization of chiral gauge theories on a latti
ce II
DTSTART;VALUE=DATE-TIME:20160726T155000Z
DTEND;VALUE=DATE-TIME:20160726T161000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2691@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Ryo Yamamura (Osaka U.)\nWe propose a 6-dimensional
lattice regularization of chiral gauge\ntheories. In our formulation\, Wey
l fermions are localized on the\njunction of two different domain-walls. O
ne domain-wall naturally\nexhibits the Stora-Zumino chain of the anomaly d
escent equations.\nAnother domain-wall mediates a similar inflow of the gl
obal anomalies.\nThe anomaly free condition is equivalent to requiring the
measure of\nthe 6-dimensional Dirac fermions to cancel the axial U(1) and
parity\nanomalies. ``Localizing'' the gauge fields on the 4-dimensional\n
junction using the Yang-Mills gradient flow\, as proposed by Grabowska\nan
d Kaplan\, we non-perturbatively define the 4-dimensional path\nintegral o
f the target chiral gauge theory.\n\nIn the first talk\, we present the ba
sic idea of our formulation\,\nemphasizing on why the 6-th dimension is ne
eded for the global\nanomalies. In the second talk\, we explain our lattic
e set-up in\ndetails.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contr
ibutions/2691/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2691/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Six-dimensional regularization of chiral gauge theories on a latti
ce I
DTSTART;VALUE=DATE-TIME:20160726T153000Z
DTEND;VALUE=DATE-TIME:20160726T155000Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2692@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Hidenori Fukaya (Osaka University)\nWe propose a 6-d
imensional lattice regularization of chiral gauge theories.\nIn our formul
ation\, Weyl fermions are localized on the junction of two\ndifferent doma
in-walls. One domain-wall naturally exhibits the\nStora-Zumino chain of th
e anomaly descent equations. Another domain-wall mediates a similar inflow
of the global anomalies. The anomaly free condition is equivalent to requ
iring the measure of the 6-dimensional Dirac fermions to cancel the axial
U(1) and parity anomalies. ``Localizing'' the gauge fields on the 4-dimens
ional junction using\nthe Yang-Mills gradient flow\, as proposed by Grabow
ska and Kaplan\, we non-perturbatively define the 4-dimensional path integ
ral of the target chiral gauge theory.\n\nIn the first talk\, we present t
he basic idea of our formulation\,\nemphasizing on why the 6-th dimension
is needed for the global anomalies.\nIn the second talk\, we explain our l
attice set-up in details.\n\nhttps://conference.ippp.dur.ac.uk/event/470/c
ontributions/2692/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2692/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Diagrammatic Monte-Carlo simulations of the large N SU(N)xSU(N) pr
incipal chiral model based on the weak-coupling trans-series expansion
DTSTART;VALUE=DATE-TIME:20160725T164500Z
DTEND;VALUE=DATE-TIME:20160725T170500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2718@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Pavel Buividovich (Regensburg University)\nI present
a Diagrammatic Monte-Carlo algorithm for the large N SU(N)xSU(N) principa
l chiral model\, which stochastically samples planar Feynman diagrams of t
he lattice perturbation theory. The latter is constructed using the Cayley
map from SU(N) group manifold to the space of Hermitian matrices. I demon
strate that the Jacobian of this map results in the massive bare lattice p
ropagator with the mass proportional to the bare coupling. This bare mass
term ensures that perturbative series are IR finite and do not have factor
ial divergences at high orders\, which makes the series suitable for Monte
-Carlo sampling and stochastic summation. On the other hand\, since the ba
re mass is proportional to the coupling itself\, the expansion is no longe
r an expansion in powers of coupling\, but rather has the form of trans-se
ries involving both powers and logs of coupling. I discuss possible resurg
ent structure of these trans-series\, the strength of the sign problem in
Monte-Carlo sampling\, as well as the extension of the present approach to
lattice gauge theory.\n\nhttps://conference.ippp.dur.ac.uk/event/470/cont
ributions/2718/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2718/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Beyond complex Langevin equations:positive representation of Feynm
an path integrals directly in the Minkowski time
DTSTART;VALUE=DATE-TIME:20160725T154500Z
DTEND;VALUE=DATE-TIME:20160725T160500Z
DTSTAMP;VALUE=DATE-TIME:20210802T030108Z
UID:indico-contribution-493-2722@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Jacek Wosiek (Jagellonian University)\nA positive re
presentation for an arbitrary complex\, gaussian weight is derived and use
d to construct a statistical formulation of gaussian path integrals direct
ly in the Minkowski time. \n\nThe positivity of Minkowski weights is achie
ved by doubling the number of real variables. The continuum limit of the n
ew representation exists only if some of the additional couplings tend to
infinity and are tuned in a specific way. The construction is then success
fully applied to three quantum mechanical examples including a particle in
a constant magnetic field -- a simplest prototype of a Wilson line. \n\nF
urther generalizations are shortly discussed and an intriguing interpretat
ion of new variables is alluded to.\n\nhttps://conference.ippp.dur.ac.uk/e
vent/470/contributions/2722/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 100
3
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2722/
END:VEVENT
END:VCALENDAR