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BEGIN:VEVENT
SUMMARY:Jade Brisson (Université Laval)
DTSTART:20221102T150000Z
DTEND:20221102T153000Z
DTSTAMP:20260404T111109Z
UID:QARF/1
DESCRIPTION:Title: <a href="https://stable.researchseminars.org/talk/QARF/
 1/">Looking for eigenvalues</a>\nby Jade Brisson (Université Laval) as pa
 rt of Quebec Analysis and Related Fields Graduate Seminar\n\n\nAbstract\nI
 n this talk\, you will be introduced to spectral geometry. We will briefly
  talk about what it is before focusing on one of the problem that is studi
 ed in this field: the Steklov problem. After a historic review of this pro
 blem\, we will focus on the following question: Can we calculate its eigen
 values?\n
LOCATION:https://stable.researchseminars.org/talk/QARF/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marcu-Antone Orsoni (University of Toronto)
DTSTART:20221116T160000Z
DTEND:20221116T163000Z
DTSTAMP:20260404T111109Z
UID:QARF/2
DESCRIPTION:Title: <a href="https://stable.researchseminars.org/talk/QARF/
 2/">Separation of singularities for the Bergman space and reachable space 
 of the heat equation</a>\nby Marcu-Antone Orsoni (University of Toronto) a
 s part of Quebec Analysis and Related Fields Graduate Seminar\n\n\nAbstrac
 t\nLet $\\Omega_1$ and $\\Omega_2$ be two open sets of the complex plane w
 ith non empty intersection. The separation of singularities problem can be
  stated as follows: if $f$ belongs to the Bergman space of $\\Omega_1 \\ca
 p \\Omega_2$\, can we find $f_1$ and $f_2$ belonging respectively to the B
 ergman spaces of $\\Omega_1$ and $\\Omega_2$\, such that $f= f_1 + f_2$? \
 nIn this talk\, we will see general settings in which the previous questio
 n has a positive answer and we will apply these results to the description
  of the reachable space of the heat equation. Joint work with Andreas Hart
 mann.\n
LOCATION:https://stable.researchseminars.org/talk/QARF/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Reihaneh Vafadar (Université Laval)
DTSTART:20221130T160000Z
DTEND:20221130T163000Z
DTSTAMP:20260404T111109Z
UID:QARF/3
DESCRIPTION:Title: <a href="https://stable.researchseminars.org/talk/QARF/
 3/">On divergence-free (form-bounded type) drifts</a>\nby Reihaneh Vafadar
  (Université Laval) as part of Quebec Analysis and Related Fields Graduat
 e Seminar\n\n\nAbstract\nWe develop regularity theory for elliptic Kolmogo
 rov operator with divergence-free drift in a large class (or\, more genera
 lly\, drift having singular divergence). A key step in our proofs is "Cacc
 ioppoli's iterations"\, used in addition to the classical De Giorgi's iter
 ations and Moser's method.\n\nThis talk is based on joint work with Damir 
 Kinzebulatov (Université Laval)\n
LOCATION:https://stable.researchseminars.org/talk/QARF/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Billel Guelmame (ENS de Lyon)
DTSTART:20221214T160000Z
DTEND:20221214T163000Z
DTSTAMP:20260404T111109Z
UID:QARF/4
DESCRIPTION:Title: <a href="https://stable.researchseminars.org/talk/QARF/
 4/">On some regularized nonlinear hyperbolic equations</a>\nby Billel Guel
 mame (ENS de Lyon) as part of Quebec Analysis and Related Fields Graduate 
 Seminar\n\n\nAbstract\nIt is known that the solutions of nonlinear hyperbo
 lic partial differential equations develop discontinuous shocks in finite 
 time even with smooth initial data. Those shock are problematic in the the
 oretical study and in the numerical computations. To avoid these shocks\, 
 many regularizations have been studied in the literature. For example\, ad
 ding diffusion and/or dispersion to the equation. In this talk\, we presen
 t and study some non-diffusive and non-dispersive regularizations of the B
 urgers equation and the barotropic Euler equations that have similar prope
 rties as the classical equations.\n
LOCATION:https://stable.researchseminars.org/talk/QARF/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Tendron (University of Oxford)
DTSTART:20230126T160000Z
DTEND:20230126T164000Z
DTSTAMP:20260404T111109Z
UID:QARF/5
DESCRIPTION:Title: <a href="https://stable.researchseminars.org/talk/QARF/
 5/">A central limit theorem for a spatial logistic branching process in th
 e slow coalescence regime</a>\nby Thomas Tendron (University of Oxford) as
  part of Quebec Analysis and Related Fields Graduate Seminar\n\n\nAbstract
 \nWe study the scaling limits of a spatial population dynamics model which
  describes the sizes of colonies located on the integer lattice\, and allo
 ws for branching\, coalescence in the form of local pairwise competition\,
  and migration. When started near the local equilibrium\, the rates of bra
 nching and coalescence in the particle system are both linear in the local
  population size - we say that the coalescence is slow. We identify a resc
 aling of the equilibrium fluctuations process under which it converges to 
 an infinite dimensional Ornstein-Uhlenbeck process with alpha-stable drivi
 ng noise if the offspring distribution lies in the domain of attraction of
  an alpha-stable law with alpha between one and two.\n
LOCATION:https://stable.researchseminars.org/talk/QARF/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mahishanka Withanachchi (Université Laval)
DTSTART:20230209T160000Z
DTEND:20230209T164000Z
DTSTAMP:20260404T111109Z
UID:QARF/6
DESCRIPTION:Title: <a href="https://stable.researchseminars.org/talk/QARF/
 6/">Polynomial approximation in local Dirichlet spaces</a>\nby Mahishanka 
 Withanachchi (Université Laval) as part of Quebec Analysis and Related Fi
 elds Graduate Seminar\n\n\nAbstract\nThe partial Taylor sums $S_n$\, $n \\
 geq 0$\, are finite rank operators on any Banach space of analytic functio
 ns on the open unit disc. In the classical setting of disc algebra\, the p
 recise value of the norm of $S_n$ is not known and thus in the literature 
 they are referred as the Lebesgue constants. In this setting\, we just kno
 w that they grow like $\\log n$\, modulo a multiplicative constant\, as $n
 $ tends to infinity. However\, on the weighted Dirichlet spaces $\\D_w$\, 
 we precisely evaluate the norm of $S_n$. As a matter of fact\, there are d
 ifferent ways to put a norm on $\\D_w$. Even though these norms are equiva
 lent\, they lead to different values for the norm of $S_n$\, as an operato
 r on $\\D_w$. We present three different norms on $\\D_w$\, and in each ca
 se we  try to obtain the precise value of the operator norm of $S_n$. Thes
 e results are in sharp contrast to the classical setting of the disc algeb
 ra. We also consider the problem for the cesaro means $\\sigma_n$ on local
  Dirichlet spaces and try to find the norm of $\\sigma_n$ precisely for th
 e three different norms that we introduced.\n
LOCATION:https://stable.researchseminars.org/talk/QARF/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alain Didier Noutchegueme (Université de Montréal)
DTSTART:20230223T160000Z
DTEND:20230223T164000Z
DTSTAMP:20260404T111109Z
UID:QARF/7
DESCRIPTION:Title: <a href="https://stable.researchseminars.org/talk/QARF/
 7/">On minimal Surface and eigenvalues isoperimetric inequalities.</a>\nby
  Alain Didier Noutchegueme (Université de Montréal) as part of Quebec An
 alysis and Related Fields Graduate Seminar\n\n\nAbstract\nIn the same way 
 that geodesics are critical curves for the length fonctional in a Riemanni
 ann Manifold\, Minimal Surfaces are critical hypersurfaces for the area fu
 nctional. \n\nIn 1996\, a passionating connection have been made between M
 inimal Surfaces in low dimensional spheres\, and extremal riemannian metri
 cs for eigenvalues of the Laplace-Beltrami operator on Compact Riemannian 
 Surfaces. The aim of this talk is to present such a connection\, and some 
 more recent extensions to more general eigenvalues problems.\n
LOCATION:https://stable.researchseminars.org/talk/QARF/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pierre-Olivier Parisé (University of Hawaii at Manoa)
DTSTART:20230406T150000Z
DTEND:20230406T154000Z
DTSTAMP:20260404T111109Z
UID:QARF/8
DESCRIPTION:Title: <a href="https://stable.researchseminars.org/talk/QARF/
 8/">Involutions of multicomplex numbers</a>\nby Pierre-Olivier Parisé (Un
 iversity of Hawaii at Manoa) as part of Quebec Analysis and Related Fields
  Graduate Seminar\n\n\nAbstract\nGiven a real algebra $A$\, a function $f 
 : A \\to A$ is called a (real)-linear involution if $f$ is (real)-linear a
 nd $f(f(a)) = a$ for any element $a \\in A$. A natural question\, at least
  when $\\dim A < \\infty$\, is: How many (real)-linear involutions are the
 re for a given complex algebra? \n\nWe will answer this question in the fi
 rst part of the talk for the commutative real algebra $\\mathbb{M}\\mathbb
 {C}(n) (n \\geq 1)$ of multicomplex numbers\, a commutative generalization
  of the complex numbers. In the second part of the talk\, I will show how 
 to define different Laplacians using the (real)-linear involutions of the 
 multicomplex numbers.\n\nThe first part of this talk is a joint work with 
 Nicolas Doyon and William Verreault.\n
LOCATION:https://stable.researchseminars.org/talk/QARF/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Antoine Metras (University of Bristol)
DTSTART:20230309T160000Z
DTEND:20230309T164000Z
DTSTAMP:20260404T111109Z
UID:QARF/9
DESCRIPTION:Title: <a href="https://stable.researchseminars.org/talk/QARF/
 9/">Eigenvalue optimisation and n-harmonic maps</a>\nby Antoine Metras (Un
 iversity of Bristol) as part of Quebec Analysis and Related Fields Graduat
 e Seminar\n\n\nAbstract\nOn a surface\, eigenvalue optimisation with respe
 ct to the metric leads to minimal surfaces (in a sphere for Laplace eigenv
 alue\, free boundary minimal in a ball for Steklov ones). When we restrict
  the optimisation problem to a conformal class\, the corresponding object 
 we obtain are harmonic maps. I will discuss generalisation to higher dimen
 sion of these results and how n-harmonic maps play a crucial role in it.\n
LOCATION:https://stable.researchseminars.org/talk/QARF/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuveshen Mooroogen (University of British Columbia)
DTSTART:20230420T150000Z
DTEND:20230420T154000Z
DTSTAMP:20260404T111109Z
UID:QARF/10
DESCRIPTION:Title: <a href="https://stable.researchseminars.org/talk/QARF/
 10/">Large subsets of Euclidean space avoiding infinite arithmetic progres
 sions</a>\nby Yuveshen Mooroogen (University of British Columbia) as part 
 of Quebec Analysis and Related Fields Graduate Seminar\n\n\nAbstract\nAn a
 rithmetic progression (AP) is a collection of equally-spaced real numbers.
  It may be finite or countably infinite. It is known that if a subset of t
 he real line has positive Lebesgue measure\, then it contains a k-term AP 
 for every natural number k. In joint work with Laurestine Bradford (McGill
 \, Linguistics) and Hannah Kohut (UBC\, Mathematics)\, we prove that this 
 result does not extend to infinite APs in the following sense: for each re
 al number p in [0\,1)\, we construct a subset of the real line that inters
 ects every interval of unit length in a set of measure at least p\, but th
 at does not contain any infinite AP. In this presentation\, I will explain
  the geometric features of our set that allow it to avoid such progression
 s. I will also briefly discuss two recent preprints\, due to Kolountzakis-
 Papageorgiou and Burgin-Goldberg-Keleti-MacMahon-Wang\, that were inspired
  by our work. These respectively employ probabilistic and topological meth
 ods\, in contrast to our argument\, which relies on measure theory and equ
 idistribution of sequences mod 1.\n
LOCATION:https://stable.researchseminars.org/talk/QARF/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nicolas Frantz (Université de Lorraine)
DTSTART:20230504T150000Z
DTEND:20230504T154000Z
DTSTAMP:20260404T111109Z
UID:QARF/11
DESCRIPTION:Title: <a href="https://stable.researchseminars.org/talk/QARF/
 11/">Introduction to scattering theory on Hilbert spaces.</a>\nby Nicolas 
 Frantz (Université de Lorraine) as part of Quebec Analysis and Related Fi
 elds Graduate Seminar\n\n\nAbstract\nThe goal of scattering theory is to w
 rite the asymptotic of solutions of Schrödinger equation associated to a 
 complex Hamiltonian in term of solutions of Schrödinger equation associat
 ed to a simpler Hamiltonian. \nAfter describing how theory of Hilbert spac
 e can describe quantum system\, I will introduce the main ideas of scatter
 ing theory for self-adjoint operator. If I have enough time\, I will expla
 in how to extend this theory to non-self-adjoint Hamiltonian.\n
LOCATION:https://stable.researchseminars.org/talk/QARF/11/
END:VEVENT
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