Ara es mostren els items 1-12 de 122

    • Homomorphisms between graphs embedded in surfaces 

      Garijo Royo, Delia; Goodall, Andrew; Vena Cros, Lluís (Elsevier, 2024-05)
      Article
      Accés obert
      We extend the notion of graph homomorphism to cellularly embedded graphs (maps) by designing operations on vertices and edges that respect the surface topology; we thus obtain the first definition of map homomorphism that ...
    • Marked graphs and the chromatic symmetric function 

      Aliste Prieto, José; Mier Vinué, Anna de; Orellana, Rosa; Zamora Ponce, José (2023-09-30)
      Article
      Accés obert
      The main result of this paper is the introduction of marked graphs and the marked graph polynomials ( -polynomial) associated with them. These polynomials can be defined via a deletion-contraction operation. These polynomials ...
    • Speeding up random walk mixing by starting from a uniform vertex 

      Espuny Díaz, Alberto; Morris, Patrick; Perarnau Llobet, Guillem; Serra Albó, Oriol (Project Euclid, 2024-01-01)
      Article
      Accés obert
      The theory of rapid mixing random walks plays a fundamental role in the study of modern randomised algorithms. Usually, the mixing time is measured with respect to the worst initial position. It is well known that the ...
    • On additive MDS codes with linear projections 

      Adriaensen, Sam; Ball, Simeon Michael (Elsevier, 2023-10-01)
      Article
      Accés obert
      We support some evidence that a long additive MDS code over a finite field must be equivalent to a linear code. More precisely, let C be an -linear MDS code over . If , , , and C has three coordinates from which its ...
    • The diameter of the directed configuration model 

      Cai, Xing Shi; Perarnau Llobet, Guillem (2023-02-01)
      Article
      Accés obert
      We show that the diameter of the directed configuration model with n vertices rescaled by log n converges in probability to a constant. Our assumptions are the convergence of the in- and out-degree of a uniform random ...
    • Approximation and decomposition in lattices of clutters 

      Martí Farré, Jaume; Mier Vinué, Anna de (2023-08-01)
      Article
      Accés obert
      A clutter on O is a family of subsets of O that are incomparable under inclusion. Given a collection S of clutters on O and another clutter ¿ on O, we study the problem of approximating and decomposing ¿ in terms of the ...
    • De la teoria de grafs clàssica a l’anàlisi de les grans xarxes 

      Rué Perna, Juan José (2023-12-21)
      Article
      Accés obert
      Actualment la teoria de grafs té un paper fonamental tant en les matemà-tiques pures com en les seves aplicacions en moltes branques del coneixement. Enaquest article recorrerem l’evolució de l’àrea de recerca partint del ...
    • Quantum error-correcting codes and their geometries 

      Ball, Simeon Michael; Centelles Tarrés, Aina; Huber, Felix (European Mathematical Society (EMS), 2023-02-10)
      Article
      Accés obert
      This is an expository article aiming to introduce the reader to the underlying mathematics and geometry of quantum error correction. Information stored on quantum particles is subject to noise and interference from the ...
    • Cut vertices in random planar maps 

      Drmota, Michael; Noy Serrano, Marcos; Stufler, Benedikt (2023-09-22)
      Article
      Accés obert
      The main goal of this paper is to determine the asymptotic behavior of the number X n of cut-vertices in random planar maps with n edges. It is shown that X n / n ¿ c in probability (for some explicit c > 0 ). For so-called ...
    • The rado multiplicity problem in vector spaces over finite fields 

      Rué Perna, Juan José; Spiegel, Christoph (Muni press, 2023)
      Comunicació de congrés
      Accés obert
      We study an analogue of the Ramsey multiplicity problem for additive structures, establishing the minimum number of monochromatic $3$-APs in $3$-colorings of $\mathbb{F}_3^n$ and obtaining the first non-trivial lower bound ...
    • Product-free sets in the free group 

      Ortega Sánchez Colomer, Miquel; Rué Perna, Juan José; Serra Albó, Oriol (2023)
      Comunicació de congrés
      Accés obert
      We prove that product-free sets of the free group over a finite alphabet have max-imum density1/2with respect to the natural measure that assigns total weight oneto each set of irreducible words of a given length. This ...
    • Random cubic planar maps 

      Drmota, Michael; Noy Serrano, Marcos; Requile, Clement; Rué Perna, Juan José (2023-06-30)
      Article
      Accés obert
      We analyse uniform random cubic rooted planar maps and obtain limiting distributions for several parameters of interest. From the enumerative point of view, we present a unified approach for the enumeration of several ...