• On the Halpern Method with Adaptive Anchoring Parameters 

      [OWP-2024-11] Pinto, Pedro; Pischke, Nicholas (Mathematisches Forschungsinstitut Oberwolfach, 2024-10-21)
      We establish the convergence of a speed-up version of the Halpern iteration with adaptive anchoring parameters in the general geodesic setting of Hadamard spaces, generalizing a recent result by He, Xu, Dong and Mei from ...
    • On the Invariants of the Cohomology of Complements of Coxeter Arrangements 

      [OWP-2018-21] Douglass, J. Matthew; Pfeiffer, Götz; Röhrle, Gerhard (Mathematisches Forschungsinstitut Oberwolfach, 2018-10-22)
      We refine Brieskorn's study of the cohomology of the complement of the reflection arrangement of a finite Coxeter group W. As a result we complete the verification of a conjecture by Felder and Veselov that gives an explicit ...
    • On the L2 Markov Inequality with Laguerre Weight 

      [OWP-2016-15] Nikolov, Geno P.; Shadrin, Alexei (Mathematisches Forschungsinstitut Oberwolfach, 2016-08-17)
    • On the Lie Algebra Structure of $HH^1(A)$ of a Finite-Dimensional Algebra A 

      [OWP-2019-10] Linckelmann, Markus; Rubio y Degrassi, Lleonard (Mathematisches Forschungsinstitut Oberwolfach, 2019-04-17)
      Let $A$ be a split finite-dimensional associative unital algebra over a field. The first main result of this note shows that if the Ext-quiver of $A$ is a simple directed graph, then $HH^1(A)$ is a solvable Lie algebra. ...
    • On the Markov inequality in the $L_2$-norm with the Gegenbauer weight 

      [OWP-2017-05] Nikolov, Geno P.; Shadrin, Alexei (Mathematisches Forschungsinstitut Oberwolfach, 2017-02-22)
      Let $w_{\lambda}(t) := (1-t^2)^{\lambda-1/2}$, where ${\lambda} > -\frac{1}{2}$, be the Gegenbauer weight function, let $\|\cdot\|_{w_{\lambda}}$ be the associated $L_2$-norm, $$ |f\|_{w_{\lambda}} = \left\{\int_{-1}^1 ...
    • On the non-analyticity locus of an arc-analytic function 

      [OWP-2009-03] Kurdyka, Krzysztof; Parusinski, Adam (Mathematisches Forschungsinstitut Oberwolfach, 2009-02-21)
      A function is called arc-analytic if it is real analytic on each real analytic arc. In real analytic geometry there are many examples of arc-analytic functions that are not real analytic. Arc analytic functions appear ...
    • On the prediction of stationary functional time series 

      [OWP-2014-06] Aue, Alexander; Dubart Norinho, Diogo; Hörmann, Siegfried (Mathematisches Forschungsinstitut Oberwolfach, 2014-04-25)
      This paper addresses the prediction of stationary functional time series. Existing contributions to this problem have largely focused on the special case of first-order functional autoregressive processes because of their ...
    • On the δ=const Collisions of Singularities of Complex Plane Curves 

      [OWP-2008-15] Kerner, Dmitry (Mathematisches Forschungsinstitut Oberwolfach, 2008)
      We study a specific class of deformations of curve singularities: the case when the singular point splits to several ones, such that the total $\delta$ invariant is preserved. These are also known as equi-normalizable or ...
    • On Unipotent Radicals of Pseudo-Reductive Groups 

      [OWP-2017-12] Bate, Michael; Martin, Benjamin; Röhrle, Gerhard; Stewart, David I. (Mathematisches Forschungsinstitut Oberwolfach, 2017-04-27)
      We establish some results on the structure of the geometric unipotent radicals of pseudo-reductive k-groups. In particular, let $k'$ be a purely inseparable field extension of k of degree $p^e$ and let $G$ denote the ...
    • On Vietoris-Rips Complexes of Ellipses 

      [OWP-2017-11] Adamaszek, Michal; Adams, Henry; Reddy, Samadwara (Mathematisches Forschungsinstitut Oberwolfach, 2017-04-25)
      For $X$ a metric space and $r > 0$ a scale parameter, the Vietoris–Rips complex $VR_<(X; r)$ (resp. $VR_≤(X; r)$) has $X$ as its vertex set, and a finite subset $\sigma \subseteq X$ as a simplex whenever the diameter of ...
    • On Weak Weighted Estimates of Martingale Transform 

      [OWP-2016-22] Nazarov, Fedor; Reznikov, Alexander; Vasyunin, Vasily; Volberg, Alexander (Mathematisches Forschungsinstitut Oberwolfach, 2016-11-12)
      We consider several weak type estimates for singular operators using the Bellman function approach. We disprove the $A_1$ conjecture, which stayed open after Muckenhoupt-Wheeden's conjecture was disproved by Reguera-Thiele.
    • On Weakly Complete Universal Enveloping Algebras of pro-Lie Algebras 

      [OWP-2020-10] Hofmann, Karl Heinrich; Kramer, Linus (Mathematisches Forschungsinstitut Oberwolfach, 2020-04-27)
    • An Optimal Bound for the Ratio Between Ordinary and Uniform Exponents of Diophantine Approximation 

      [OWP-2018-15] Marnat, Antoine; Moshchevitin, Nikolay (Mathematisches Forschungsinstitut Oberwolfach, 2018-07-09)
      We provide a lower bound for the ratio between the ordinary and uniform exponents of both simultaneous Diophantine approximation to n real numbers and Diophantine approximation for one linear form in n variables. This ...
    • Optimal bounds for the colored Tverberg Problem 

      [OWP-2009-27] Blagojevic, Pavle V. M.; Matschke, Benjamin; Ziegler, Günter M. (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-20)
      We prove a "Tverberg type" multiple intersection theorem. It strengthens the prime case of the original Tverberg theorem from 1966, as well as the topological Tverberg theorem of Bárány et al. (1980), by adding color ...
    • Overlap Synchronisation in Multipartite Random Energy Models 

      [OWP-2017-13] Genovese, Giuseppe; Tantari, Daniele (Mathematisches Forschungsinstitut Oberwolfach, 2017-04-29)
      In a multipartite random energy model, made of coupled GREMs, we determine the joint law of the overlaps in terms of the ones of the single GREMs. This provides the simplest example of the so-called synchronisation of the ...
    • The Pelletier-Ressayre Hidden Symmetry for Littlewood-Richardson Coefficients 

      [OWP-2020-18] Grinberg, Darij (Mathematisches Forschungsinstitut Oberwolfach, 2020-09-08)
      We prove an identity for Littlewood–Richardson coefficients conjectured by Pelletier and Ressayre. The proof relies on a novel birational involution defined over any semifield.
    • Plethysms, replicated Schur functions and series, with applications to vertex operators 

      [OWP-2010-12] Fauser, Bertfried; Jarvis, Peter D.; King, Ronald C. (Mathematisches Forschungsinstitut Oberwolfach, 2010-03-14)
      Specializations of Schur functions are exploited to define and evaluate the Schur functions $s_\lambda [\alpha X]$ and plethysms $s_\lambda [\alpha s_\nu(X))]$ for any $\alpha$-integer, real or complex. Plethysms are then ...
    • Plethystic Vertex Operators and Boson-Fermion Correspondences 

      [OWP-2016-11] Fauser, Bertfried; Jarvis, Peter D.; King, Ronald C. (Mathematisches Forschungsinstitut Oberwolfach, 2016-06-17)
      We study the algebraic properties of plethystic vertex operators, introduced in J. Phys. A: Math. Theor. 43 405202 (2010), underlying the structure of symmetric functions associated with certain generalized universal ...
    • Pointwise hyperbolicity implies uniform hyperbolicity 

      [OWP-2009-06] Hasselblatt, Boris; Pesin, Yakov B.; Schmeling, Jörg (Mathematisches Forschungsinstitut Oberwolfach, 2009-02-23)
      We provide a general mechanism for obtaining uniform information from pointwise data. A sample result is that if a diffeomorphism of a compact Riemannian manifold has pointwise expanding and contracting continuous invariant ...
    • Polynomiality, wall crossings and tropical geometry of rational double hurwitz cycles 

      [OWP-2012-13] Bertram, Aaron; Cavalieri, Renzo; Markwig, Hannah (Mathematisches Forschungsinstitut Oberwolfach, 2012-12-04)
      We study rational double Hurwitz cycles, i.e. loci of marked rational stable curves admitting a map to the projective line with assigned ramification profiles over two fixed branch points. Generalizing the phenomenon ...