Diego Alejandro Mejía

dblp:129/0609 · DBLP profile ↗
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6ranked-venue papers
1as first author
4since 2021 · last 2025
0000-0003-3203-1891ORCID · reported

Domains — the database's venue-derived domains; a paper can count in several

Theory of computation · 6 · 1 first-author · 4 since 2021
YearPublicationVenuePosition
2025 More about the cofinality and the covering of the ideal of strong measure zero sets
Miguel A. Cardona, Diego Alejandro Mejía
Ann. Pure Appl. Log.2
2025 Lebesgue Measure Zero Modulo ideals on the Natural numbers
abstract
Abstract We propose a reformulation of the ideal $\mathcal {N}$ of Lebesgue measure zero sets of reals modulo an ideal J on $\omega $ , which we denote by $\mathcal {N}_J$ . In the same way, we reformulate the ideal $\mathcal {E}$ generated by $F_\sigma $ measure zero sets of reals modulo J, which we denote by $\mathcal {N}^*_J$ . We show that these are $\sigma $ -ideals and that $\mathcal {N}_J=\mathcal {N}$ iff J has the Baire property, which in turn is equivalent to $\mathcal {N}^*_J=\mathcal {E}$ . Moreover, we prove that $\mathcal {N}_J$ does not contain co-meager sets and $\mathcal {N}^*_J$ contains non-meager sets when J does not have the Baire property. We also prove a deep connection between these ideals modulo J and the notion of nearly coherence of filters (or ideals). We also study the cardinal characteristics associated with $\mathcal {N}_J$ and $\mathcal {N}^*_J$ . We show their position with respect to Cichoń’s diagram and prove consistency results in connection with other very classical cardinal characteristics of the continuum, leaving just very few open questions. To achieve this, we discovered a new characterization of $\mathrm {add}(\mathcal {N})$ and $\mathrm {cof}(\mathcal {N})$ . We also show that, in Cohen model, we can obtain many different values to the cardinal characteristics associated with our new ideals.
Viera Gavalová, Diego Alejandro Mejía
J. Symb. Log.2
2024 Continuum many different things: Localisation, anti-localisation and Yorioka ideals
Miguel A. Cardona, Lukas Daniel Klausner, Diego Alejandro Mejía
Ann. Pure Appl. Log.3
2021 Filter-linkedness and its effect on preservation of cardinal characteristics
Jörg Brendle, Miguel A. Cardona, Diego Alejandro Mejía
Ann. Pure Appl. Log.3
2018 Coherent Systems of finite Support iterations
abstract
Abstract We introduce a forcing technique to construct three-dimensional arrays of generic extensions through FS (finite support) iterations of ccc posets, which we refer to as 3D-coherent systems. We use them to produce models of new constellations in Cichoń’s diagram, in particular, a model where the diagram can be separated into 7 different values. Furthermore, we show that this constellation of 7 values is consistent with the existence of a ${\rm{\Delta }}_3^1$ well-order of the reals.
Vera Fischer, Sy-David Friedman, Diego Alejandro Mejía, Diana Carolina Montoya
J. Symb. Log.3
2015 Template iterations with non-definable ccc forcing notions
Diego Alejandro Mejía
Ann. Pure Appl. Log.1