In the article by Arttu Rajantie on the search for magnetic monopoles, I noticed there was no mention of other monopole searches that had negative results. The most significant of those is the work by Luis Alvarez and his co-authors.1,2,3 The references to Rajantie’s figure 4, the plot of monopole flux versus monopole mass, cite experiments by Alvarez and his colleagues. A description of the implications of their work would have been helpful.

1.
P. H.
Eberhard
,
R. R.
Ross
,
L. W.
Alvarez
,
R. D.
Watt
,
Phys. Rev. D
4
,
3260
(
1971
).
2.
R. R.
Ross
,
P. H.
Eberhard
,
L. W.
Alvarez
,
R. D.
Watt
,
Phys. Rev. D
8
,
698
(
1973
).
3.
L. W.
Alvarez
,
P. H.
Eberhard
,
R. R.
Ross
,
R. D.
Watt
, in
Proceedings of the Apollo 11 Lunar Science Conference
,
vol. 3, Pergamon Press
(
1970
), p.
1953
.
4.
Arttu
Rajantie
,
Physics Today
69
(
10
),
40
(
2016
).