Reflection implies the SCH

Saharon Shelah

Fundamenta Mathematicae (2008)

  • Volume: 198, Issue: 2, page 95-111
  • ISSN: 0016-2736

Abstract

top
We prove that, e.g., if μ > cf(μ) = ℵ₀ and μ > 2 and every stationary family of countable subsets of μ⁺ reflects in some subset of μ⁺ of cardinality ℵ₁, then the SCH for μ⁺ holds (moreover, for μ⁺, any scale for μ⁺ has a bad stationary set of cofinality ℵ₁). This answers a question of Foreman and Todorčević who get such a conclusion from the simultaneous reflection of four stationary sets.

How to cite

top

Saharon Shelah. "Reflection implies the SCH." Fundamenta Mathematicae 198.2 (2008): 95-111. <http://eudml.org/doc/286118>.

@article{SaharonShelah2008,
abstract = {We prove that, e.g., if μ > cf(μ) = ℵ₀ and $μ > 2^\{ℵ₀\}$ and every stationary family of countable subsets of μ⁺ reflects in some subset of μ⁺ of cardinality ℵ₁, then the SCH for μ⁺ holds (moreover, for μ⁺, any scale for μ⁺ has a bad stationary set of cofinality ℵ₁). This answers a question of Foreman and Todorčević who get such a conclusion from the simultaneous reflection of four stationary sets.},
author = {Saharon Shelah},
journal = {Fundamenta Mathematicae},
keywords = {reflection; stationary sets; singular cardinal hypothesis; pcf},
language = {eng},
number = {2},
pages = {95-111},
title = {Reflection implies the SCH},
url = {http://eudml.org/doc/286118},
volume = {198},
year = {2008},
}

TY - JOUR
AU - Saharon Shelah
TI - Reflection implies the SCH
JO - Fundamenta Mathematicae
PY - 2008
VL - 198
IS - 2
SP - 95
EP - 111
AB - We prove that, e.g., if μ > cf(μ) = ℵ₀ and $μ > 2^{ℵ₀}$ and every stationary family of countable subsets of μ⁺ reflects in some subset of μ⁺ of cardinality ℵ₁, then the SCH for μ⁺ holds (moreover, for μ⁺, any scale for μ⁺ has a bad stationary set of cofinality ℵ₁). This answers a question of Foreman and Todorčević who get such a conclusion from the simultaneous reflection of four stationary sets.
LA - eng
KW - reflection; stationary sets; singular cardinal hypothesis; pcf
UR - http://eudml.org/doc/286118
ER -

NotesEmbed ?

top

You must be logged in to post comments.

To embed these notes on your page include the following JavaScript code on your page where you want the notes to appear.

Only the controls for the widget will be shown in your chosen language. Notes will be shown in their authored language.

Tells the widget how many notes to show per page. You can cycle through additional notes using the next and previous controls.

    
                

Note: Best practice suggests putting the JavaScript code just before the closing </body> tag.