Browsing Department of Pure Mathematics and Mathematical Statistics (DPMMS) by Issue Date

Now showing items 101-120 of 248

  • Bulk eigenvalue statistics for random regular graphs 

    Bauerschmidt, Roland; Huang, Jiaoyang; Knowles, Antti; Yau, Horng-Tzer (Institute of Mathematical StatisticsAnnals of Probability, 2016)
    We consider the uniform random d-regular graph on N vertices, with d ∈ [N$^{\alpha}$,N$^{2/3−\alpha}$] for arbitrary α > 0. We prove that in the bulk of the spectrum the local eigenvalue correlation functions and the ...

  • A Paley-like graph in characteristic two 

    Thomason, Andrew Gordon (Journal of Combinatorics, 2016)
    The Paley graph is a well-known self-complementary pseudo-random graph, defined over a finite field of odd order. We describe an attempt at an analogous construction using fields of even order. Some properties of the graph ...

  • Proof of a conjecture of Batyrev and Nill 

    Favero, David; Kelly, Tyler Lee (Johns Hopkins University PressAmerican Journal of Mathematics, 2016)
    We prove equivalences of derived categories for the various mirrors in the Batyrev-Borisov construction. In particular, we obtain a positive answer to a conjecture of Batyrev and Nill. The proof involves passing to an ...

  • Modelling Interactions in High-dimensional Data with Backtracking 

    Shah, Rajen Dinesh (Journal of Machine Learning ResearchJournal of Machine Learning Research, 2016)
    We study the problem of high-dimensional regression when there may be interacting variables. Approaches using sparsity-inducing penalty functions such as the Lasso (Tibshirani, 1996) can be useful for producing interpretable ...

  • On the Cauchy Problem for the Homogeneous Boltzmann-Nordheim Equation for Bosons: Local Existence, Uniqueness and Creation of Moments 

    Briant, Marc; Einav, Amit (SpringerJournal of Statistical Physics, 2016)
    The Boltzmann-Nordheim equation is a modification of the Boltzmann equation, based on physical considerations, that describes the dynamics of the distribution of particles in a quantum gas composed of bosons or fermions. ...

  • Alpha invariants and coercivity of the Mabuchi functional on Fano manifolds 

    Dervan, Ruadhai (Université Paul SabatierAnnales de la Faculté des Sciences de Toulouse, 2016)
    We give a criterion for the coercivity of the Mabuchi functional for general Kàhler classes on Fano manifolds in terms of Tian's alpha invariant. This generalises a result of Tian in the anti-canonical case implying the ...

  • On K-stability of finite covers 

    Dervan, Ruadhai (Oxford University PressJournal of the London Mathematical Society, 2016)
    We show that certain Galois covers of K-semistable Fano varieties are K-stable. We use this to give some new examples of Fano manifolds admitting Kähler-Einstein metrics, including hypersurfaces, double solids and threefolds.

  • Statistical and computational trade-offs in estimation of sparse principal components 

    Wang, Tengyao; Berthet, Quentin; Samworth, Richard John (Institute of Mathematical StatisticsAnnals of Statistics, 2016)
    In recent years, Sparse Principal Component Analysis has emerged as an extremely popular dimension reduction technique for highdimensional data. The theoretical challenge, in the simplest case, is to estimate the leading ...

  • A 2-adic automorphy lifting theorem for unitary groups over CM fields 

    Thorne, Jack Arfon (SpringerMathematische Zeitschrift, 2016)
    We prove a ‘minimal’ type automorphy lifting theorem for 2-adic Galois representations of unitary type, over imaginary CM fields. We use this to improve an automorphy lifting theorem of Kisin for GL_2.

  • Automorphy of some residually S$_5$ Galois representations 

    Khare, Chandrashekhar B.; Thorne, Jack A. (SpringerMathematische Zeitschrift, 2016)
    Let $\textit{F}$ be a totally real field and $\textit{p}$ an odd prime. We prove an automorphy lifting theorem for geometric representations $\rho$ : $\textit{G}_F$ → GL$_2$($\bar{\Bbb Q}_p$) which lift irreducible residual ...

  • Envelopes of positive metrics with prescribed singularities 

    Ross, Julius; Nyström, David Witt (Université Paul Sabatier, ToulouseAnnales de la Faculté des Sciences de Toulouse, 2016)
    We investigate envelopes of positive metrics with a prescribed singularity type. First we generalise work of Berman to this setting, proving C$^{1,1}$ regularity of such envelopes, showing their Monge-Ampère measure is ...

  • On the rigid cohomology of certain Shimura varieties. 

    Harris, Michael; Lan, Kai-Wen; Taylor, Richard; Thorne, Jack Arfon (SpringerResearch in the Mathematical Sciences, 2016)
    We construct the compatible system of $\textit{l}$-adic representations associated to a regular algebraic cuspidal automorphic representation of GL$_{n}$ over a CM (or totally real) field and check local-global compatibility ...

  • Variation of Gieseker moduli spaces via quiver GIT 

    Greb, Daniel; Ross, Julius Andrew; Toma, Matei (Mathematical Sciences PublishersGeometry & Topology, 2016)
    We introduce a notion of stability for sheaves with respect to several polarisations that generalises the usual notion of Gieseker-stability. We prove, under a boundedness assumption, which we show to hold on threefolds ...

  • Quantifying separability in virtually special groups 

    Hagen, Mark Fearghus; Patel, Priyam (Mathematical Society PublishingPacific Journal of Mathematics, 2016)
    We give a new, effective proof of the separability of cubically convex-cocompact subgroups of special groups. As a consequence, we show that if G is a virtually compact special hyperbolic group, and Q ≤ G is a K-quasiconvex ...

  • Cubulating hyperbolic free-by-cyclic groups: the irreducible case 

    Hagen, Mark Fearghus; Wise, Daniel T (Duke University PressDuke Mathematical Journal, 2016)
    Let V be a fi nite graph and let ∅ : V → V be an irreducible train track map whose mapping torus has word-hyperbolic fundamental group G. Then G acts freely and cocompactly on a CAT(0) cube complex. Hence, if F is a ...

  • D-modules on rigid analytic spaces I 

    Ardakov, Konstantin; Wadsley, Simon James (De GruyterJournal für die reine und angewandte Mathematik, 2016)
    We introduce a sheaf of infinite order differential operators D on smooth rigid analytic spaces that is a rigid analytic quantisation of the cotangent bundle. We show that the sections of this sheaf over sufficiently small ...

  • Global Rates of Convergence in Log-Concave Density Estimation 

    Kim, Arlene KH; Samworth, Richard John (Institute of Mathematical StatisticsAnnals of Statistics, 2016)
    The estimation of a log-concave density on $\Bbb R$$^d$ represents a central problem in the area of nonparametric inference under shape constraints. In this paper, we study the performance of log-concave density estimators ...

  • Tests for separability in nonparametric covariance operators of random surfaces 

    Aston, John Alexander; Pigoli, Davide; Tavakoli, Shahin (Institute of Mathematical StatisticsAnnals of Statistics, 2016)
    The assumption of separability of the covariance operator for a random image or hypersurface can be of substantial use in applications, especially in situations where the accurate estimation of the full covariance structure ...

  • Homological Stability for Spaces of Embedded Surfaces 

    Moran, Federico Cantero; Randal-Williams, Oscar (Mathematical Sciences PublisherGeometry & Topology, 2016)
    We study the space of oriented genus $\textit{g}$ subsurfaces of a fixed manifold $\textit{M}$, and in particular its homological properties. We construct a “scanning map” which compares this space to the space of sections ...

  • Peter Hall’s Work on High-Dimensional Data and Classification 

    Samworth, Richard John (Institute of Mathematical StatisticsAnnals of Statistics, 2016)
    In this article, I summarise Peter Hall’s contributions to high-dimensional data, including their geometric representations and variable selection methods based on ranking. I also discuss his work on classification problems, ...