### From Wikipedia, the free encyclopedia

**José Luis Massera** (June 8, 1915–September 9,
2002)^{[1]}^{[2]} was an
Uruguayan mathematician who
researched the stability of differential equations. Massera's
lemma is named after him. He published over 40 papers during
1940–1970. A militant Communist, he was a political prisoner
during 1975–1984.

In the 1930s, Rey Pastor gave regular weekend lectures on topology in Montevideo to a group
that included Massera. Stimulated by contact with Argentine
mathematics, the 1950s saw Uruguay develop a fine school in mathematics, of which
Massera was very much a part of.^{[3]}

Massera developed new notions of stability, and published
several foundational papers and an influential textbook. His
results in (Massera 1950) on
periodic differential equations have been heavily cited and are
referred to as Massera's theorem. His work in (Massera 1949) and (Massera 1956) on the converse to Lyapunov's criterion is also
influential, and contain the well known Massera's
lemma. His textbook (Massera & Schäffer
1966) is also heavily cited.

In 1971, at age 62, Massera was elected to the senate as an
alternate senator.^{[4]} After
military intervention in Uruguay in 1973,^{[5]} Massera
was arrested on October 22, 1975 in Montevideo and was held in solitary
confinement for nearly a year. During this time he was
subjected to repeated torture resulting in injuries including a fractured pelvis. In October 1976 he was taken from
solitary confinement, tried and convicted for "subversive
association", and given a 24-year prison sentence.^{[6]} He was
released in 1984.^{[7]}

## Selected
works

**Massera, José Luis** (1949), "On
Liapounoff's conditions of stability", *Annals
of Mathematics. Second Series* **50**:
705–721, doi:10.2307/1969558, MR0035354
**Massera, José Luis** (1950), "The existence of periodic
solutions of systems of differential equations", *Duke Mathematical
Journal* **17**: 457–475, doi:10.1215/S0012-7094-50-01741-8, MR0040512, http://projecteuclid.org/getRecord?id=euclid.dmj/1077476236
**Massera, José Luis** (1956), "Contributions
to stability theory", *Annals of Mathematics. Second
Series* **64**: 182–206, doi:10.2307/1969955, MR0079179
**Massera, José Luis**; Schäffer, Juan Jorge
(1966), *Linear differential equations and function spaces*,
Pure and Applied Mathematics, Vol. 21, Boston, MA: Academic Press,
MR0212324

## References

**^**
Broué, M.;
Gonzalez-Sprinberg, G. (2002), "José Luis Massera
(1915–2002)", *Gazette des Mathématiciens*
**94**: 8, MR2067167, http://smf.emath.fr/en/Publications/Gazette/2002/94/smf_gazette_94_8-8.pdf
.
**^**
Kahane,
J.-P. (2002), "José Luis Massera",
*Gazette des Mathématiciens* **94**: 9–13, MR2067168, http://smf.emath.fr/en/Publications/Gazette/2002/94/smf_gazette_94_9-13.pdf
.
**^**
Bethell, Leslie (1996). *Ideas and
Ideologies in Twentieth Century Latin America*. Cambridge
University Press. pp. 336. Bethell. ISBN
0521468337.
**^**
Joyce, James Avery (1978). *Human
Rights: International Documents*. Brill Archive. pp. 1529.
joyce. ISBN
9028602984.
**^**
Bethell, Leslie (1996). *Ideas and
Ideologies in Twentieth Century Latin America*. Cambridge
University Press. pp. 336. Bethell. ISBN
0521468337.
**^**
Joyce, James Avery (1978). *Human
Rights: International Documents*. Brill Archive. pp. 1529.
joyce. ISBN
9028602984.
**^**
MR0712764