Department of Pure Mathematics and Mathematical Statistics (DPMMS): Recent submissions

Now showing items 181-200 of 248

  • Freiman homomorphisms on sparse random sets 

    Conlon, D; Gowers, William Timothy (Oxford University PressQuarterly Journal of Mathematics, 2017-02-03)
    A result of Fiz Pontiveros shows that if $A$ is a random subset of $\mathbb{Z}_N$ where each element is chosen independently with probability $N^{-1/2+o(1)}$, then with high probability every Freiman homomorphism defined ...

  • L-space intervals for graph manifolds and cables 

    Rasmussen, Sarah Dean (Cambridge University PressCompositio Mathematica, 2017-05)
    We present a graph manifold analog of the Jankins–Neumann classification of Seifert fibered spaces over $S^2$ admitting taut foliations, providing a finite recursive formula to compute the L-space Dehn-filling interval for ...

  • Tubular free by cyclic groups act freely on CAT(0) cube complexes 

    Button, Jack (Canadian Mathematical SocietyCanadian Mathematical Bulletin, 2017-03-01)
    We identify when a tubular group (the fundamental group of a finite graph of groups with $\mathbb{Z}$$^{2}$ vertex and $\mathbb{Z}$ edge groups) is free by cyclic and show, using Wise's equitable sets criterion, that every ...

  • Exceptional collections, and the Néron–Severi lattice for surfaces 

    Vial, Charles Louis (ElsevierAdvances in Mathematics, 2017-01-10)
    We work out properties of smooth projective varieties X over a (not necessarily algebraically closed) field $\textit{k}$ that admit collections of objects in the bounded derived category of coherent sheaves D$^{b}$(X) that ...

  • Gaussian tree constraints applied to acoustic linguistic functional data 

    Shiers, Nathaniel; Aston, John Alexander; Smith, Jim Q; Coleman, John S (ElsevierJournal of Multivariate Analysis, 2016-10-11)
    Evolutionary models of languages are usually considered to take the form of trees. With the development of so-called tree constraints the plausibility of the tree model assumptions can be assessed by checking whether the ...

  • Topological cycle matroids of infinite graphs 

    Carmesin, Johannes (ElsevierEuropean Journal of Combinatorics, 2017-02-01)
    We prove that the topological cycles of an arbitrary infinite graph together with its topological ends form a matroid. This matroid is, in general, neither finitary nor cofinitary.

  • INVARIANT DISTRIBUTIONS AND THE GEODESIC RAY TRANSFORM 

    Paternain, Gabriel Pedro; Zhou, Hanming (Mathematical Science PublishersAnalysis & PDE, 2016-12-11)
    We establish an equivalence principle between the solenoidal injectivity of the geodesic ray transform acting on symmetric $\textit{m}$-tensors and the existence of invariant distributions or smooth first integrals with ...

  • Non-Backtracking Loop Soups and Statistical Mechanics on Spin Networks 

    Camia, Federico; Lis, Marcin (SpringerAnnales Henri Poincaré, 2016-10-20)
    We introduce and study a Markov field on the edges of a graph $\mathcal{G}$ in dimension $\textit{d}$ ≥ 2 whose configurations are spin networks. The field arises naturally as the edge-occupation field of a Poissonian model ...

  • Acylindrical Hyperbolicity, non-simplicity and SQ-universality of groups splitting over $\mathbb{Z}$ 

    Button, Jack (De GruyterJournal of Group Theory, 2016-09-15)
    We show, using acylindrical hyperbolicity, that a finitely generated group splitting over $\mathbb{Z}$ cannot be simple. We also obtain SQ-universality in most cases, for instance a balanced group (one where if two powers ...

  • Uniform Bounds for Black--Scholes Implied Volatility 

    Tehranchi, Michael Rummine (Society for Industrial and Applied MathematicsSIAM Journal on Financial Mathematics, 2016-11-29)
    In this note, Black--Scholes implied volatility is expressed in terms of various optimization problems. From these representations, upper and lower bounds are derived which hold uniformly across moneyness and call price. ...

  • 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 ...

  • Homogeneous Monge-Amp$\grave e$re Equations and Canonical Tubular Neighbourhoods in Kähler Geometry 

    Ross, Julius Andrew; Nyström, David Witt (Oxford University PressInternational Mathematics Research Notices, 2016)
    We prove the existence of canonical tubular neighbourhoods around complex submanifolds of Kähler manifolds that are adapted to both the holomorphic and symplectic structure. This is done by solving the complex Homogeneous ...

  • Data processing for the sandwiched Rényi divergence: a condition for equality 

    Leditzky, Felix; Rouzé, Cambyse; Datta, Nilanjana (SpringerLetters in Mathematical Physics, 2016)
    The $\alpha$-sandwiched Rényi divergence satisfies the data processing inequality, i.e. monotonicity under quantum operations, for $\alpha$ $\geq$ 1/2. In this article, we derive a necessary and sufficient algebraic condition ...

  • SMOOTH PRINCIPAL COMPONENT ANALYSIS OVER TWO-DIMENSIONAL MANIFOLDS WITH AN APPLICATION TO NEUROIMAGING 

    Lila, Eardi; Aston, John Alexander; Sangalli, Laura M (Institute of Mathematical StatisticsThe Annals of Applied Statistics, 2016-01-05)
    Motivated by the analysis of high-dimensional neuroimaging signals located over the cortical surface, we introduce a novel Principal Component Analysis technique that can handle functional data located over a two-dimensional ...

  • Level lines of the Gaussian free field with general boundary data 

    Powell, Ellen
    We study the level lines of a Gaussian free field in a planar domain with general boundary data F. We show that the level lines exist as continuous curves under the assumption that F is regulated (i.e., admits finite left ...

  • Asymptotics of Partial Density Functions for Divisors 

    Ross, Julius; Singer, Michael (SpringerThe Journal of Geometric Analysis, 2016-09-19)
    We study the asymptotic behaviour of the partial density function associated to sections of a positive hermitian line bundle that vanish to a particular order along a fixed divisor $Y$ . Assuming the data in question is ...

  • Unstable mode solutions to the Klein-Gordon equation in Kerr-anti-de Sitter spacetimes 

    Dold, Dominic (SpringerCommunications in Mathematical Physics, 2016)
    For any cosmological constant Λ = −3/$l^2$ < 0 and any $\alpha$ < 9/4, we find a Kerr-AdS spacetime ($M$, $g_{KAdS}$), in which the Klein-Gordon equation $\square g_{KAdS}$ ψ+$\alpha$/$l^2$ψ = 0 has an exponentially growing ...

  • Isometric disks are holomorphic 

    Antonakoudis, Stergios (SpringerInventiones mathematicae, 2016-10-05)
    This paper shows that every totally-geodesic isometry from the unit disk to a finite-dimensional Teichmüller space for the intrinsic Kobayashi metric is either holomorphic or anti-holomorphic; in particular, it is a ...

  • Nonhyperbolic free-by-cyclic and one-relator groups 

    Button, Jack; Kropholler, RP (New York Journal of MathematicsNew York Journal of Mathematicshttp://nyjm.albany.edu/j/2016/22-35.html, 2016-08-01)
    We show that the free-by-cyclic groups of the form $F_2$ $\rtimes$ $\Bbb Z$ act properly cocompactly on CAT(0) square complexes. We also show using generalized Baumslag–Solitar groups that all known groups defined by a ...

  • How old are you, really? Communicating chronic risk through ‘effective age’ of your body and organs 

    Spiegelhalter, David John (BioMed CentralBMC Medical Informatics and Decision Making, 2016-08-05)
    In communicating chronic risks, there is increasing use of a metaphor that can be termed ‘effective-age’: the age of a ‘healthy’ person who has the same risk profile as the individual in question. Popular measures include ...