• closedAccess   A formula for the conductor of a semimodule of a numerical semigroup with two generators 

      Almirón, Patricio; Moyano-Fernández, Julio José Springer (2021-03-30)
      We provide an expression for the conductor c(Δ) of a semimodule Δ of a numerical semigroup Γ with two generators in terms of the syzygy module of Δ and the generators of the semigroup. In particular, we deduce that the ...
    • openAccess   Basic actions to reduce dropout rates in distance learning 

      Gregori, Pablo; Martínez, Vicente; Moyano-Fernández, Julio José (2018-02)
      Today’s society, which is strongly based on knowledge and interaction with information, has a key component in technological innovation, a fundamental tool for the development of the current teaching methodologies. Nowadays, ...
    • openAccess   Duality and syzygies for semimodules over numerical semigroups 

      Moyano-Fernández, Julio José; Uliczka, Jan Springer Verlag (2015-02)
      Let Γ=⟨α,β⟩ be a numerical semigroup. In this article we consider the dual Δ∗ of a Γ-semimodule Δ; in particular we deduce a formula that expresses the minimal set of generators of Δ∗ in terms of the generators of Δ. As ...
    • openAccess   Eliahou number, Wilf function and concentration of a numerical semigroup 

      Almirón, Patricio; Moyano-Fernández, Julio José Taylor & Francis (2022-03-30)
      We give an estimate of the minimal positive value of the Wilf function of a numerical semigroup in terms of its concentration. We describe necessary conditions for a numerical semigroup to have a negative Eliahou number ...
    • openAccess   Fractional ideals and integration with respect to the generalised Euler characteristic 

      Moyano-Fernández, Julio José Springer (2015)
      Let bb be a fractional ideal of a one-dimensional Cohen–Macaulay local ring containing a perfect field. This paper is devoted to the study of the motivic Poincaré series defined by different filtrations associated with bb ...
    • openAccess   Hilbert regularity of Z-graded modules over polynomial rings 

      Bruns, Winfried; Moyano-Fernández, Julio José; Uliczka, Jan Rocky Mountain Mathematics Consortium (2017-06)
      Let M be a finitely generated Z-graded module over the standard graded polynomial ring R=K[X1,…,Xd] with K a field, and let HM(t)=QM(t)/(1−t)d be the Hilbert series of~M. We introduce the Hilbert regularity of~M as the ...
    • openAccess   Hilbert series of modules over positively graded polynomial rings 

      Katthan, Lukas; Moyano-Fernández, Julio José; Uliczka, Jan Elsevier (2016-08)
      In this note, we give examples of formal power series satisfying certain conditions that cannot be realized as Hilbert series of finitely generated modules. This answers to the negative a question raised in a recent article ...
    • openAccess   How to compute the Stanley depth of a module 

      Ichim, Bogdan; Katthan, Lukas; Moyano-Fernández, Julio José American Mathematical Society (2017)
      In this paper we introduce an algorithm for computing the Stanleydepth of a finitely generated multigraded module M over the polynomialring K[X1,...,Xn]. As an application, we give an example of a module whoseStanley depth ...
    • openAccess   Lattice paths with given number of turns and semimodules over numerical semigroups 

      Moyano-Fernández, Julio José; Uliczka, Jan Springer US (2014-06)
      Let Γ =< α, ß> be a numerical semigroup. In this article we consider several relations between the so-called Γ -semimodules and lattice paths from (0, α) to (ß,0): we investigate isomorphism classes of Γ -semimodules as ...
    • openAccess   LCM Lattices and Stanley Depth: A First Computational Approach 

      Ichim, Bogdan; Katthän, Lukas; Moyano-Fernández, Julio José Taylor & Francis (2015-10)
      Let K be a field, and let S D K [X1, . . . ,Xn] be the polynomial ring. Let / be a monomial ideal of S with up to 5 generators. In this paper, we present a computational experiment which allows us to prove that depthS ...
    • openAccess   Linear optics only allows every possible quantum operation for one photon or one port 

      Moyano-Fernández, Julio José; García-Escartín, Juan Carlos Elsevier (2017)
      We study the evolution of the quantum state of n photons in m different modes when they go through a lossless linear optical system. We show that there are quantum evolution operators U that cannot be built with linear ...
    • openAccess   Method to determine which quantum operations can be realized with linear optics with a constructive implementation recipe 

      García-Escartín, Juan Carlos; Gimeno, Vicent; Moyano-Fernández, Julio José American Physical Society (2019)
      The evolution of quantum light through linear optical devices can be described by the scattering matrix S of the system. For linear optical systems with m possible modes, the evolution of n input photons is given by a ...
    • openAccess   Minimal plane valuations 

      Galindo, Carlos; Monserrat, Francisco; Moyano-Fernández, Julio José American Mathematical Society (AMS) (2018-07)
      We consider the value u(v)=lim m->m-1 a(mL) , where a(mL) is the last value of the vanishing sequence of Hº(mL) along a divisorial or irrational valuation v centered at Op2,p ,L (respectively, P ) being a line ...
    • openAccess   Multiple photon effective Hamiltonians in linear quantum optical networks 

      García-Escartín, Juan Carlos; Gimeno, Vicent; Moyano-Fernández, Julio José Elsevier (2019)
      We give an alternative derivation for the explicit formula of the effective Hamiltonian describing the evolution of the quantum state of any number of photons entering a linear optics multiport. The description is based ...
    • openAccess   Newton–Okounkov bodies of exceptional curve valuations 

      Galindo, Carlos; Moyano-Fernández, Julio José; Monserrat, Francisco; Nickel, Matthias European Mathematical Society (2020-03-20)
      We prove that the Newton–Okounkov body associated to the flag E∙:={X=Xr⊃Er⊃{q}}, defined by the surface X and the exceptional divisor Er given by any divisorial valuation of the complex projective plane P2, with respect ...
    • openAccess   No-go theorems for photon state transformations in quantum linear optics 

      V. Parellada, Pablo; Gimeno i Garcia, Vicent; Moyano-Fernández, Julio José; Garcia-Escartin, Juan Carlos Elsevier (2023)
      We give a necessary condition for photon state transformations in linear optical setups preserving the total number of photons. From an analysis of the algebra describing the quantum evolution, we find a conserved quantity ...
    • openAccess   On the score sheets of a round-robin football tournament 

      Ichim, Bogdan; Moyano-Fernández, Julio José Elsevier (2017-10)
      The set of (ordered) score sheets of a round-robin football tournament played between n teams together with the pointwise addition has the structure of an affine monoid. In this paper we study (using both theoretical and ...
    • openAccess   Optimal approximation to unitary quantum operators with linear optics 

      Garcia-Escartin, Juan Carlos; Gimeno, Vicent; Moyano-Fernández, Julio José Springer Nature (2021-09-21)
      Linear optical systems acting on photon number states produce many interesting evolutions, but cannot give all the allowed quantum operations on the input state. Using Toponogov’s theorem from differential geometry, we ...
    • openAccess   Poincaré series for curve singularities and its behaviour under projections 

      Moyano-Fernández, Julio José Elsevier (2015)
      Let O be an equicharacteristic reduced complete noetherian local ring of Krull dimension one, and let S be the value semigroup associated with O. The aim of the paper is to investigate the behaviour of the multi-variable ...
    • openAccess   QOptCraft: A Python package for the design and study of linear optical quantum systems 

      Gomez-Aguado, Daniel; Gimeno, Vicent; Moyano-Fernández, Julio José; Garcia-Escartin, Juan Carlos Elsevier (2022-08-29)
      The manipulation of the quantum states of light in linear optical systems has multiple applications in quantum optics and quantum computation. The package QOptCraft gives a collection of methods to solve some of the most ...