81 citations · 338 across the 34 of their papers we have counts for
46 papers
PhaseJumps: fast computation of zeros from planar grid samples
Antti Haimi, Günther Koliander, José Luis Romero
We consider complex-valued functions on the complex plane and the task of computing their zeros from samples taken along a finite grid. We introduce PhaseJumps, an algorithm based…
Sampling in the shift-invariant space generated by the bivariate Gaussian function
José Luis Romero, Alexander Ulanovskii, Ilya Zlotnikov
We study the space spanned by the integer shifts of a bivariate Gaussian function and the problem of reconstructing any function in that space from samples scattered across the pla…
Random periodic sampling patterns for shift-invariant spaces
Jorge Antezana, Diana Carbajal, José Luis Romero
We consider multi-variate signals spanned by the integer shifts of a set of generating functions with distinct frequency profiles and the problem of reconstructing them from sample…
Eigenvalue estimates for Fourier concentration operators on two domains
Felipe Marceca, José Luis Romero, Michael Speckbacher
We study concentration operators associated with either the discrete or the continuous Fourier transform, that is, operators that incorporate a spatial cut-off and a subsequent fre…
Improved discrepancy for the planar Coulomb gas at low temperatures
Felipe Marceca, José Luis Romero
We study the planar Coulomb gas in the regime where the inverse temperature grows at least logarithmically with respect to the number of particles (freezing regime, $β_n\…
Comment on "Affine density, von Neumann dimension and a problem of Perelomov"
José Luis Romero
We point out that the main theorem of Ref2 := [Adv. Math. 407, Article ID 108564, 22 p. (2022)] is included in the prior research survey Ref1 := [Expo. Math., 40(2), 265-301, 2022]…
Normality of smooth statistics for planar determinantal point processes
Antti Haimi, José Luis Romero
We consider smooth linear statistics of determinantal point processes on the complex plane, and their large scale asymptotics. We prove asymptotic normality in the finite variance…
Estimation of binary time-frequency masks from ambient noise
José Luis Romero, Michael Speckbacher
We investigate the retrieval of a binary time-frequency mask from a few observations of filtered white ambient noise. Confirming household wisdom in acoustic modeling, we show that…
On the existence of optimizers for time-frequency concentration problems
Fabio Nicola, José Luis Romero, S. Ivan Trapasso
We consider the problem of the maximum concentration in a fixed measurable subset of the time-frequency space for functions . Th…
Spectral-norm risk rates for multi-taper estimation of Gaussian processes
José Luis Romero, Michael Speckbacher
We consider the estimation of the covariance of a stationary Gaussian process on a multi-dimensional grid from observations taken on a general acquisition domain. We derive spectra…
Efficient computation of the zeros of the Bargmann transform under additive white noise
Luis Alberto Escudero, Naomi Feldheim, Günther Koliander +1
We study the computation of the zero set of the Bargmann transform of a signal contaminated with complex white noise, or, equivalently, the computation of the zeros of its short-ti…
Spectral deviation of concentration operators for the short-time Fourier transform
Felipe Marceca, José Luis Romero
Time-frequency concentration operators restrict the integral analysis-synthesis formula for the short-time Fourier transform to a given compact domain. We estimate how much the cor…
Zeros of Gaussian Weyl-Heisenberg functions and hyperuniformity of charge
Antti Haimi, Günther Koliander, José Luis Romero
We study Gaussian random functions on the complex plane whose stochastics are invariant under the Weyl-Heisenberg group (twisted stationarity). The theory is modeled on translation…
The planar low temperature Coulomb gas: separation and equidistribution
Yacin Ameur, José Luis Romero
We consider planar Coulomb systems consisting of a large number of repelling point charges in the low temperature regime, where the inverse temperature grows at least logar…
Sign retrieval in shift-invariant spaces with totally positive generator
José Luis Romero
We show that a real-valued function in the shift-invariant space generated by a totally positive function of Gaussian type is uniquely determined, up to a sign, by its absolute…
Sampling the flow of a bandlimited function
Akram Aldroubi, Karlheinz Gröchenig, Longxiu Huang +3
We analyze the problem of reconstruction of a bandlimited function from the space-time samples of its states resulting from the convolution with a kernel .…
Multiple sampling and interpolation in weighted Fock spaces of entire functions
Luis Alberto Escudero, Antti Haimi, José Luis Romero
We characterize sampling and interpolating sets with derivatives in weighted Fock spaces on the complex plane in terms of their weighted Beurling densities.
The density theorem for discrete series representations restricted to lattices
José Luis Romero, Jordy Timo van Velthoven
This article considers the relation between the spanning properties of lattice orbits of discrete series representations and the associated lattice co-volume. The focus is on the d…
On dual molecules and convolution-dominated operators
José Luis Romero, Jordy Timo van Velthoven, Felix Voigtlaender
We show that sampling or interpolation formulas in reproducing kernel Hilbert spaces can be obtained by reproducing kernels whose dual systems form molecules, ensuring that the siz…
Balian-Low type theorems on homogeneous groups
Karlheinz Gröchenig, José Luis Romero, David Rottensteiner +1
We prove strict necessary density conditions for coherent frames and Riesz sequences on homogeneous groups. Let be a connected, simply connected nilpotent Lie group with a dila…
Invertibility of frame operators on Besov-type decomposition spaces
José Luis Romero, Jordy Timo van Velthoven, Felix Voigtlaender
We derive an extension of the Walnut-Daubechies criterion for the invertibility of frame operators. The criterion concerns general reproducing systems and Besov-type spaces. As an…
Multitaper estimation on arbitrary domains
Joakim Andén, José Luis Romero
Multitaper estimators have enjoyed significant success in estimating spectral densities from finite samples using as tapers Slepian functions defined on the acquisition domain. Unf…
The Nyquist sampling rate for spiraling curves
Philippe Jaming, Felipe Negreira, José Luis Romero
We consider the problem of reconstructing a compactly supported function from samples of its Fourier transform taken along a spiral. We determine the Nyquist sampling rate in terms…
Strict density inequalities for sampling and interpolation in weighted spaces of holomorphic functions
Karlheinz Gröchenig, Antti Haimi, Joaquim Ortega-Cerdà +1
Answering a question of Lindholm, we prove strict density inequalities for sampling and interpolation in Fock spaces of entire functions in several complex variables defined by a p…