more from this thinker     |     more from this text


Single Idea 17890

[filed under theme 6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity ]

Full Idea

Some of the standard large cardinals (in order of increasing (logical) strength) are: inaccessible, Mahlo, weakly compact, indescribable, Erdös, measurable, strong, Wodin, supercompact, huge etc. (...and ineffable).

Gist of Idea

There are at least eleven types of large cardinal, of increasing logical strength

Source

Peter Koellner (On the Question of Absolute Undecidability [2006], 1.4)

Book Ref

-: 'Philosophia Mathematica' [-], p.10


A Reaction

[I don't understand how cardinals can have 'logical strength', but I pass it on anyway]


The 10 ideas with the same theme [infinity as a collection of transcendent size]:

Cardinality strictly concerns one-one correspondence, to test infinite sameness of size [Cantor, by Maddy]
You can't get a new transfinite cardinal from an old one just by adding finite numbers to it [Russell]
For every transfinite cardinal there is an infinite collection of transfinite ordinals [Russell]
Very large sets should be studied in an 'if-then' spirit [Putnam]
First-order logic can't discriminate between one infinite cardinal and another [Hodges,W]
For any cardinal there is always a larger one (so there is no set of all sets) [Maddy]
Infinity has degrees, and large cardinals are the heart of set theory [Maddy]
An 'inaccessible' cardinal cannot be reached by union sets or power sets [Maddy]
There are at least eleven types of large cardinal, of increasing logical strength [Koellner]
Paradox: there is no largest cardinal, but the class of everything seems to be the largest [Lavine]