## Real Analysis Exchange

### Martin’s axiom and maximal orthogonal families.

Saharon Shelah

#### Abstract

It is shown that Martin's Axiom for $\sigma$-centered partial orders implies that every maximal orthogonal family in $\mathbb{R}^\mathbb{N}$ is of size $2^{\aleph_0}$.

#### Article information

Source
Real Anal. Exchange, Volume 28, Number 2 (2002), 477-480.

Dates
First available in Project Euclid: 20 July 2007

https://projecteuclid.org/euclid.rae/1184963810

Mathematical Reviews number (MathSciNet)
MR2010330

Zentralblatt MATH identifier
1044.03040

#### Citation

Shelah, Saharon. Martin’s axiom and maximal orthogonal families. Real Anal. Exchange 28 (2002), no. 2, 477--480. https://projecteuclid.org/euclid.rae/1184963810

#### References

• A. W. Miller and J. Steprāns, Orthogonal families of real sequences, J. Symbolic Logic, 63 (1998), 29–49.