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A solution to the telescope conjecture,
June, 2023.
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| In June 2023, a disproof of the telescope conjecture for chromatic
heights ≥ 2 was announced by
Robert Burklund,
Jeremy Hahn,
Ishan Levy
and Tomer Schlank at the Panorama of Homotopy Theory Conference
at the Mathematical Institute, Oxford University.
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Jeremy, Tomer, myself, Ishan and Robert at Oxford University, June 9, 2023. Photo by Matteo Barucco.
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Videos of their four talks in Oxford:
- Ishan
Levy, June 6. The lecture begins at 17:00.
- Tomer Schlank, June 7. The lecture begins at 18:00.
- Jeremy Hahn, June 8. This video includes a lecture by Soren Galatius. Jeremy's talk starts at 1:27:00.
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Robert Burklund, June 9. The lecture begins at 18:30.
In each case you should put the window on the upper left in full screen mode.
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| Their preprint appeared on October 26, 2023.
K-theoretic counterexamples to Ravenel's telescope conjecture.
All items in their bibliography can be found in my archive.
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NEW
In 2024 Ishan won a Clay Research Fellowship.
April 14, 2026, from
the Clay Mathematics Institute:
A Clay Research Award is made to Robert Burklund
(Copenhagen), Jeremy Hahn (MIT), Ishan Levy (IAS and
CMI), and Tomer Schlank (Chicago) in recognition of
their remarkable construction of counterexamples to
Ravenel's Telescope Conjecture.
The Telescope Conjecture was the last open conjecture from Ravenel's
visionary paper Localization with respect to certain periodic
homology theories. That paper, and the body of work it inspired, form
the bedrock of chromatic homotopy theory. In one version, the
telescope conjecture postulates an upper bound on the growth rate of
the chromatic layers of the stable homotopy groups of spheres. The
work of Burklund, Hahn, Levy and Schlank is the crest of a
revolutionary new wave in K-theoretic techniques, to which they have
each, independently, contributed. Their counterexamples imply that the
p-rank of the stable homotopy groups of spheres grows faster than
expected, and contains a proliferation of elements that are
unaccountable by any prior understanding of the subject. This is a
milestone achievement.
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| In 2024 they led
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Some background material.
- NEW I have recently
written two expository papers on the backgound of the BHLS
proof, What are cyclotomic spectra and why do we
need them? and Cyclotomic extensions in stable homotopy
theory
- The conjecture first appeared
in Localization with respect to certain
periodic homology theories, 1984, as 10.5.
- My Glasgow lecture of May 24, 2022,
"What is the telescope conjecture? A walking tour of modern homotopy
theory."
Slides.
Zoom
video recording. This talk was given for a general
audience. It includes an account of "Morava's vision," which
was first described in his unpublished 1972
preprint, The moduli variety for formal groups,
recently transcribed by John Rognes. Jack sent
me this
long lost copy shortly after I gave the talk. It was later
retypeset by John
Rognes here.
- Slides for my introduction to
the Princeton
Special Algebraic Topology Seminar of October 28, 2023,
which featured lectures by each of the four authors.
Contact Tony Bahri
for notes on their
talks. Print friendly
version of my slides.
- I gave
an eCHT
minicourse (4 lectures) in December 2023. It covered the
background and motivation for the conjecture, but not the BHLS
disproof of it.
- For deeper background on the algebraic apparatus behind the
conjecture, see my first
book, Complex
cobordism and stable homotopy groups of spheres, also known
as the green book.
- For more information about the chromatic filtration of the stable homotopy category, see my second
book, Nilpotence and periodicity in stable homotopy theory, also known
as the orange book.
Graduate course by Mark Behrens
on Algebraic K-theory and the telescope conjecture, Fall 2023. This site includes handwritten lecture notes and videos.
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Quanta story of August 22, 2023
Podcast of January 24, 2024
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