• Media type: E-Article
  • Title: Boolean algebras with no rigid or homogeneous factors
  • Contributor: Štěpánek, Petr
  • imprint: American Mathematical Society (AMS), 1982
  • Published in: Transactions of the American Mathematical Society
  • Language: English
  • DOI: 10.1090/s0002-9947-1982-0642333-3
  • ISSN: 0002-9947; 1088-6850
  • Keywords: Applied Mathematics ; General Mathematics
  • Origination:
  • Footnote:
  • Description: <p>A simple construction of Boolean algebras with no rigid or homogeneous factors is described. It is shown that for every uncountable cardinal <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="kappa"> <mml:semantics> <mml:mi>κ<!-- κ --></mml:mi> <mml:annotation encoding="application/x-tex">\kappa</mml:annotation> </mml:semantics> </mml:math> </inline-formula> there are <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="2 Superscript kappa"> <mml:semantics> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mn>2</mml:mn> <mml:mi>κ<!-- κ --></mml:mi> </mml:msup> </mml:mrow> <mml:annotation encoding="application/x-tex">{2^\kappa }</mml:annotation> </mml:semantics> </mml:math> </inline-formula> isomorphism types of Boolean algebras of power <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="kappa"> <mml:semantics> <mml:mi>κ<!-- κ --></mml:mi> <mml:annotation encoding="application/x-tex">\kappa</mml:annotation> </mml:semantics> </mml:math> </inline-formula> with no rigid or homogeneous factors. A similar result is obtained for complete Boolean algebras for certain regular cardinals. It is shown that every Boolean algebra can be completely embedded in a complete Boolean algebra with no rigid or homogeneous factors in such a way that the automorphism group of the smaller algebra is a subgroup of the automorphism group of the larger algebra. It turns out that the cardinalities of antichains in both algebras are the same. It is also shown that every <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="kappa"> <mml:semantics> <mml:mi>κ<!-- κ --></mml:mi> <mml:annotation encoding="application/x-tex">\kappa</mml:annotation> </mml:semantics> </mml:math> </inline-formula>-distributive complete Boolean algebra can be completely embedded in a <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="kappa"> <mml:semantics> <mml:mi>κ<!-- κ --></mml:mi> <mml:annotation encoding="application/x-tex">\kappa</mml:annotation> </mml:semantics> </mml:math> </inline-formula>-distributive complete Boolean algebra with no rigid or homogeneous factors.</p>
  • Access State: Open Access