Bounded Symbiosis and Upwards Reflection

Lorenzo Galeotti; Yurii Khomskii; Jouko Väänänen

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arXiv · 2007.14718

Bounded Symbiosis and Upwards Reflection

Lorenzo Galeotti·Yurii Khomskii·Jouko Väänänen

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Abstract

Bagaria and V\"a\"an\"anen developed a framework for studying the large cardinal strength of downwards L\"owenheim-Skolem theorems and related set theoretic reflection properties. The main tool was the notion of symbiosis, originally introduced by the third author. Symbiosis provides a way of relating model theoretic properties of strong logics to definability in set theory. In this paper we continue the systematic investigation of symbiosis and apply it to upwards L\"owenheim-Skolem theorems and reflection principles. To achieve this, we need to adapt the notion of symbiosis to a new form, called bounded symbiosis. As one easy application, we obtain upper and lower bounds for the large cardinal strength of upwards L\"owenheim-Skolem-type principles for second order logic.

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BibTeX RIS

Lorenzo Galeotti, Yurii Khomskii, Jouko Väänänen. 2020-07-29. Bounded Symbiosis and Upwards Reflection. https://arxiv.org/abs/2007.14718

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