Peer-reviewedCC BY 4.0Monatshefte Fur Mathematik
Critical embeddings
- 1School of Mathematics, University of Leeds, Leeds, LS2 9JT UK
Abstract
Hayut and the first author isolated the notion of a critical cardinal in [1]. In this work, we answer several questions raised in the original paper. We show that it is consistent for a critical cardinal not to have any ultrapower elementary embeddings, as well as that it is consistent that no target model is closed. We also prove that if κ κ is a critical point by any ultrapower embedding, then it is the critical point of an ultrapower embedding by a normal measure. The paper concludes by presenting several open questions of interest in the study of critical cardinals.
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BibTeX
@article{karagila2026critical,
title = {{Critical embeddings}},
author = {Asaf Karagila and Jiachen Yuan},
journal = {Monatshefte Fur Mathematik},
year = {2026},
month = sep,
doi = {10.1007/s00605-026-02215-0},
url = {https://doi.org/10.1007/s00605-026-02215-0},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Critical embeddings
AU - Asaf Karagila
AU - Jiachen Yuan
PY - 2026
DA - 2026/09/18
JO - Monatshefte Fur Mathematik
DO - 10.1007/s00605-026-02215-0
UR - https://doi.org/10.1007/s00605-026-02215-0
AB - Hayut and the first author isolated the notion of a critical cardinal in [1]. In this work, we answer several questions raised in the original paper. We show that it is consistent for a critical cardinal not to have any ultrapower elementary embeddings, as well as that it is consistent that no target model is closed. We also prove that if κ κ is a critical point by any ultrapower embedding, then it is the critical point of an ultrapower embedding by a normal measure. The paper concludes by presenting several open questions of interest in the study of critical cardinals.
SN - 0026-9255
SN - 1436-5081
ER -