Videos and presentation materials from other INI events are also available.
Event  When  Speaker  Title  Presentation Material 

KAHW01 
13th January 2020 10:00 to 11:00 
Charles Weibel 
Ktheory and motivic cohomology  1
Constructions and basic properties of Ktheory


KAHW01 
13th January 2020 11:30 to 12:30 
Charles Doran  CalabiYau Manifolds, Mirrors, and Motives  1  
KAHW01 
13th January 2020 13:30 to 14:30 
Vesna Stojanoska  Introduction to Motivic Homotopy Theory I: Motivic Spaces  
KAHW01 
13th January 2020 14:30 to 15:30 
Charles Weibel 
Ktheory and motivic cohomology  2
Motivic Cohomology, and basic theorems


KAHW01 
13th January 2020 16:00 to 17:00 
Francis Brown  Periods, cohomology of algebraic varieties and beyond  1  
KAHW01 
14th January 2020 10:00 to 11:00 
Charles Doran  CalabiYau Manifolds, Mirrors, and Motives  2  
KAHW01 
14th January 2020 11:30 to 12:30 
Anthony Scholl  Algebraic Cycles and Hodge Theory I  
KAHW01 
14th January 2020 13:30 to 14:30 
Vesna Stojanoska  Introduction to Motivic Homotopy Theory II: Motivic Spectra  
KAHW01 
14th January 2020 14:30 to 15:30 
Charles Weibel 
Ktheory and motivic cohomology  3
The connection between Ktheory and motivic cohomology


KAHW01 
14th January 2020 16:00 to 17:00 
Matthias Flach  Special values of Motivic Lfunctions I  1  
KAHW01 
15th January 2020 09:00 to 10:00 
Charles Doran  CalabiYau Manifolds, Mirrors, and Motives  3  
KAHW01 
15th January 2020 10:00 to 11:00 
Francis Brown  Periods, cohomology of algebraic varieties and beyond  2  
KAHW01 
15th January 2020 11:30 to 12:30 
Vesna Stojanoska  Introduction to Motivic Homotopy Theory III: Highlights and Applications  
KAHW01 
16th January 2020 10:00 to 11:00 
Matthias Flach  Special values of Motivic Lfunctions II  2  
KAHW01 
16th January 2020 11:30 to 12:30 
Francis Brown  Periods, cohomology of algebraic varieties and beyond  3  
KAHW01 
16th January 2020 13:30 to 14:30 
Anthony Scholl  Algebraic Cycles and Hodge Theory II  
KAH 
16th January 2020 14:45 to 15:45 
Study group on recent work of GolyshevZagier on the gamma conjecture in mirror symmetry and of BlochVlasenko on motivic gamma functions.  
KAH 
16th January 2020 14:45 to 15:45 
Study group on recent work of GolyshevZagier on the gamma conjecture in mirror symmetry and of BlochVlasenko on motivic gamma functions. (copy)  
KAHW01 
17th January 2020 10:00 to 11:00 
Anthony Scholl  Algebraic Cycles and Hodge Theory III  
KAHW01 
17th January 2020 11:30 to 12:30 
Matthias Flach  Zeta  functions of arithmetic schemes  3  
KAH 
20th January 2020 15:00 to 16:00 
Patrick Brosnan 
Toroidal compactifications and incompressibility of exceptional congruence covers.
Suppose a finite group G acts faithfully on an irreducible variety
X. We say that the Gvariety X is compressible if there is a dominant
rational morphism from X to a faithful Gvariety Y of strictly smaller
dimension. Otherwise we say that X is incompressible.
In a recent preprint, Farb, Kisin and Wolfson (FKW) have proved the
incompressibility of a large class of covers related to the moduli
space of principally polarized abelian varieties with level
structure. Their arithmetic methods, which use SerreTate coordinates
in an ingenious way, apply to diverse examples such as moduli spaces
of curves and many Shimura varieties of Hodge type. My talk will be
about joint work with Fakhruddin and Reichstein, where our goal is to
recover some of the results of FKW via the fixed point method from the
theory of essential dimension. More specifically, we prove
incompressibility for some Shimura varieties by proving the existence
of fixed points of finite abelian subgroups of G in smooth
compactifications.
Our results are weaker than the results of FKW for Hodge type Shimura
varieties, because the methods of FKW apply in cases where there is no
boundary, while we need a nonempty boundary to find fixed
points. However, our method has the advantage of extending to many
Shimura varieties which are not of Hodge type, in particular, those
associated to groups of type E7. Moreover, by using Pink's extension
of the Ash, Mumford, Rapoport and Tai theory of toroidal
compactifications to mixed Shimura varieties, we are able to prove
incompressibility for congruence covers corresponding to certain
universal families: e.g., the universal families of principally
polarized abelian varieties.


KAH 
23rd January 2020 11:15 to 12:15 
Hossein Movasati 
Variational Hodge conjecture and Hodge loci
Grothendieck’s variational Hodge conjecture
(VHC) claims that if we have a continuous family of Hodge cycles (flat section of the GaussManin connection)
and the Hodge conjecture is true at least for one Hodge cycle of the family
then it must be true for all such Hodge cycles. A stronger version of this
(Alternative Hodge conjecture, AHC),
asserts that the deformation of an algebraic cycle Z togther with the
projective variety X, where it lives, is
the same as the deformation of the cohomology class of Z in X. There are many
simple counterexamples to AHC, however, in explict situations, like algebraic
cycles inside hypersurfaces, it becomes a challenging problem. In this talk I will review few cases in which
AHC is true (including Bloch's semiregular and local complete
intersection algebraic cycles) and other
cases in which it is not true. The talk
is mainly based on the article
arXiv:1902.00831. 

KAH 
23rd January 2020 15:00 to 16:00 
Don Zagier  Study group on recent work of GolyshevZagier on the gamma conjecture in mirror symmetry and of BlochVlasenko on motivic gamma functions. (copy)  
KAH 
27th January 2020 15:00 to 16:00 
Masha Vlasenko 
Gamma functions, monodromy and Apéry constants
In their paper on the gamma conjecture in mirror
symmetry, Golyshev and Zagier introduce a sequence of Apéry constants
associated to an ordinary linear differential operator with a choice of two
singular points and a path between them. Their setting also involves
assumptions on the local monodromies around the two points (maximally unipotent
and reflection point respectively). In particular, these assumptions are
satisfied in the situation of Apéry's proof of irrationality of zeta(3), and in
this case Golyshev and Zagier discover that (numerically, with high precision)
the higher constants in the sequence seem to be rational linear combinations of
weighted products of zeta and multiple zeta values. In the joint work with
Spencer Bloch we show that, quite generally, the generating series of Apéry
constants is a Mellin transform of a solution of the adjoint differential
operator. This peculiar property explains why Apéry constants of geometric
differential operators are periods, which seems to be the first step in the
study of their motivic nature.


KAH 
29th January 2020 11:15 to 12:15 
Takamichi Sano  On the local Tamagawa number conjecture and functional equations of Euler systems  
KAH 
29th January 2020 16:00 to 17:00 
Spencer Bloch 
Rothschild Lecture: Elliptic curves associated to twoloop graphs (Feynman diagrams)
Two loop Feynman diagrams give rise to interesting cubic hypersurfaces in n variables, where n is the number of edges. When n=3, the cubic is obviously an elliptic curve. (In fact, a family of elliptic curves parametrized by physical parameters like momentum and masses.) Remarkably, elliptic curves appear also for suitable graphs with n=5 and n=7, and conjecturally for an infinite sequence of graphs with n odd. I will describe the algebraic geometry involved in proving this. Physically, the amplitudes associated to oneloop graphs are known to be dilogarithms. Time permitting, I will speculate a bit about how the presence of elliptic curves might point toward relations between twoloop amplitudes and elliptic dilogarithms.


KAH 
30th January 2020 11:15 to 12:15 
Gabriela Guzman  Rational and plocal motivic homotopy theory  
KAH 
30th January 2020 15:00 to 16:00 
Masha Vlasenko  Study group  
KAH 
3rd February 2020 15:00 to 16:00 
John Christian Ottem 
Enriques surface fibrations with nonalgebraic integral Hodge classes
I will explain a construction of a certain
pencil of Enriques surfaces with nonalgebraic integral Hodge classes of
nontorsion type. This gives the first example of a threefold with trivial
Chow group of zerocycles on which the integral Hodge conjecture fails. If time
permits, I will explain an application to a classical question of Murre on
the universality of the AbelJacobi maps in codimension three. This is
joint work with Fumiaki Suzuki. 

KAH 
6th February 2020 11:15 to 12:15 
Clélia Pech 
Motivic integration for some varieties with a torus action
Motivic integration was introduced by Kontsevich in 1995
and has proved useful in birational geometry and singularity theory. It assigns
to constructible subsets of the arc space of a variety a "volume"
which takes values in the Grothendieck ring of algebraic varieties, and it
behaves in many ways just like usual integration.
I will explain how motivic integration can be used to
compute Batyrev's "stringy invariants", which are a generalization of
Hodge numbers to singular varieties, for a family of varieties with a torus
action. A potential application is to the study of mirror symmetry for these
varieties. (Joint with K. Langlois and M. Raibaut.)


KAH 
6th February 2020 14:30 to 15:30 
Spencer Bloch  GolyshevZagier Second Paper  
KAH 
10th February 2020 15:00 to 16:00 
Paul Balmer  Tensortriangular fields  
KAH 
13th February 2020 11:15 to 12:15 
Nicolas Garrel 
Mixed graded structures for the Ktheory of Azumaya algebras
If we encode Morita theory for Ralgebras as a
monoidal category where morphisms are bimodules, then algebraic Ktheory
becomes a (lax) monoidal functor from this category to graded abelian groups.
We show that if we restrict to Azumaya algebras, strong symmetry properties
coming from the Goldman element allow to coherently lift certain Brauer
subgroups to the the level of Morita equivalences, which gives rise to
(graded)commutative algebras of Ktheory, graded over the corresponding Brauer
subgroup. We also study analogue constructions for hermitian Ktheory of
Azumaya algebras with involution 

KAH 
17th February 2020 15:00 to 16:00 
Veronika Ertl  A rigid analytic approach to HyodoKato theory  
KAH 
20th February 2020 11:15 to 12:15 
Martin Gallauer 
Motivic ttgeometry
This
talk shall be an introduction to the field of motivic tensortriangular geometry. We hope to convey some of its flavor by explaining recent developments, and to discuss several possible directions for future research. 

KAH 
24th February 2020 15:00 to 16:00 
Mao Sheng 
Arithmetic version of Deligne’s semisimplicity theorem, and beyond.
A fundamental result in the theory of variation of Hodge
structure is the Deligne’s semisimplicity theorem. In this talk, I am going to
present an arithmetic version of this theorem. The novel thing is the introduction
of the notion of periodic logarithmic de Rham/Higgs bundles. A basic result,
which underlies the arithmetic semisimplicity theorem, is that a geometric
logarithmic de Rham/Higgs bundle is periodic. We conjecture the converse, and
in particular we shall propose the Semisimplicity conjecture: a periodic
logarithmic de Rham/Higgs bundle is semisimple. I shall explain an unexpected
relation between a very special case of the Semisimplicity conjecture with a
basic result of N. Elkies: there exist infinitely many supersingular primes for
any elliptic curve defined over $\mathbb Q$. This is a joint work with Raju
Krishnamoorthy.


KAH 
26th February 2020 11:15 to 12:15 
Jose Burgos Gil 
Higher height paining and extensions of mixed Hodge structures.
The height pairing between algebraic cycles over global
fields is an important arithmetic invariant. It can be written as sum
of
local contributions, one for each place of the ground field.
Following Hain, the Archimedean components of the height pairing can be
interpreted in terms of biextensions of mixed Hodge structures. In this talk we
will explore how to extend the Archimedean contribution of the height pairing
to higher cycles in the Bloch complex and interpret it as an
invariant associated to a mixed Hodge structure. This is joint work with
S. Goswami and G. Pearlstein.


KAH 
27th February 2020 11:15 to 12:15 
Claudio Pedrini 
The transcendental motive of a a cubic fourfold
The
transcendental part $t(X)$ of the motive of a cubic fourfold $X$ is
isomorphic to the (twisted) transcendental part $h^{tr}_2(F(X))$ in a suitable
ChowK\"unneth decomposition for the motive of the Fano variety of lines
$F(X)$. Similarly to the case of a cubic 3fold, the transcendental motive
$t(X)$ is isomorphic to the {\it Prym motive} associated to the surface $S_l
\subset F(X)$ of lines meeting a general line $l$. If $X$ is a special cubic
fourfold in the sense of Hodge theory, and $F(X) \simeq S^{[2]}$, with
$S$ a K3 surface then $t(X)\simeq t_2(S)(1)$, where $t_2(S)$
is the transcendental motive. If $X$ is very general then $t(X)$ cannot
be isomorphic to the (twisted) transcendental motive of a surface. The
existence of an isomorphism $t(X) \simeq t_2(S)(1)$ is related to
the conjectures by Hassett and Kuznetsov on the rationality of a special
cubic fourfold. I will also consider the case of other
hyperK\"alher varieties than $F(X)$ associated to a cubic fourfold $X$. 

KAH 
2nd March 2020 15:00 to 16:00 
James Plowman 
A construction of Witt complexes via residual complexes.
The Witt complex of a scheme can be thought of as the negative
degree part of Gersten complexes for MilnorWitt Ktheory. Depending on the
data of a residual complex, we will describe generalisations of the classical
second residue homormophism for Witt groups  which are the prototype for the
boundary maps appearing in the Witt complex. We'll sketch why our residue
homomorphisms assemble to form a Witt complex  even in characteristic 2  with
a focus on understanding the similarities between our construction and Balmer's


KAH 
5th March 2020 11:15 to 12:15 
Jens Hornbostel 
ChowWitt groups and the real cycle class map.
We sketch and motivate the construction of ChowWitt groups, also known as oriented Chow groups. Then we discuss some known computations. Finally, we study the real cycle class map to integral singular cohomology. This is joint work with M. Wendt, H. Xie and M. Zibrowius.


KAH 
9th March 2020 15:00 to 16:00 
Souvik Goswami 
Higher arithmetic Chow groups.
We give a new definition of higher
arithmetic Chow groups for smooth projective varieties defined over a number
field, which is similar to Gillet and Soulé's definition of arithmetic Chow
groups. We also give a compact description of the intersection theory of such
groups. A consequence of this theory is the definition of a height pairing
between two higher algebraic cycles, of complementary dimensions, whose real regulator
class is zero. This description agrees with Beilinson's height pairing for the
classical arithmetic Chow groups. We also give examples of the higher
arithmetic intersection pairing in dimension zero that is given by the
BlochWigner dilogarithm functions. This is based on the joint work with José
Burgos Gil (https://doi.org/10.1016/j.aim.2019.02.003).


KAH 
12th March 2020 11:15 to 12:15 
Anthony Scholl 
Regulators and the plectic polylogarithm
I will discuss the
construction of the "plectic plylogarithm" (a refinement of the abelian polylogarithm of Wildeshaus) and potential applications to higher regulators and special values of Lfunctions. This is joint work with Jan Nekovář (Sorbonne, Paris). 

KAH 
12th March 2020 16:00 to 17:00 
Pearl sttein  
KAH 
16th March 2020 15:00 to 16:00 
David Loeffler 
Iwasawa theory, special values of Lfunctions, and regulators, I.
I will give a brief introduction to some of the conjectures relating
special values of Lfunctions to regulators of motivic cohomology classes, such
as Beilinson's conjecture and the BlochKato conjecture. I will then describe
the padic 'mirror image' of these conjectures proposed by PerrinRiou, and how
the methods of Iwasawa theory can be used to make substantial progress on these
padic conjectures. I will illustrate this with the examples of the Riemann
zeta function and the Lfunctions of elliptic curves, and some more recent developments if time allows. 

KAH 
17th March 2020 15:00 to 16:00 
Charles Weibel  Ktheory and motivic cohomology (including the Lichtenbaum conjecture for zetaF(12i)).  
KAH 
18th March 2020 15:00 to 16:00 
Charles Weibel  Motivic homotopy and motivic cohomology.  
KAHW02 
23rd March 2020 11:30 to 12:30 
Federico Binda  CANCELLED tba  
KAHW02 
23rd March 2020 14:30 to 15:30 
Takeshi Saito 
CANCELLED Graded quotients of ramification groups of a local field with imperfect residue field
Filtration by ramification groups of the Galois group of an extension of local fields with possibly imperfect residue fields is defined by Abbes and the speaker. The graded quotients are abelian groups and annihilated by the residue characteristic. We discuss the main ingredients of the proof and the construction of injections of the character groups of the graded quotients. 

KAHW02 
23rd March 2020 16:00 to 17:00 
Gunnar Carlsson 
CANCELLED Representation theoretic models for the algebraic Ktheory of fields
Motivic cohomology provides the E_2term of a spectral
sequence converging to the algebraic Ktheory of a field F. It does not directly take into account the
absolute Galois group of F. It turns out
that there is a geometric model for the algebraic Ktheory of F, build out of
the higher dimensional representations of its absolute Galois group. I will discuss results, conjectures, and
approaches. This is joint work with Roy
Joshua. 

KAHW02 
24th March 2020 10:00 to 11:00 
Marc Hoyois 
CANCELLED Milnor excision for motivic spectra
Let k be a field and E a motivic spectrum over k
which is ntorsion for some n invertible in k. We show that the cohomology
theory on kschemes defined by E satisfies Milnor excision. More generally, we
give necessary and sufficient conditions for a cdh sheaf to satisfy Milnor
excision, following ideas of Bhatt and Mathew. Along the way, we show that the
cdh ∞topos of a quasicompact quasiseparated scheme of finite valuative
dimension is hypercomplete, extending a theorem of Voevodsky to nonnoetherian
schemes. 

KAHW02 
24th March 2020 11:30 to 12:30 
Christian Haesemeyer 
CANCELLED On Ktheories of monoids
Sets
with actions by a monoid A are a nonlinear analogue of categories of modules,
and can be used to define various flavours of Ktheory of the monoid in
question. Ktheory (using projective Asets) and Gtheory (using finitely
generated ones) have been previously studied, but do not relate in the expected
way. I will discuss joint work with Weibel clarifying why this is the case, and
introducing an intermediate category of Asets whose Ktheory exhibits the
behaviour analogous to that of the Ktheory of finitely generates modules in
the linear context 

KAHW02 
24th March 2020 13:30 to 14:30 
Free Time  
KAHW02 
24th March 2020 14:30 to 15:30 
Kirsten Wickelgren 
CANCELLED A1Euler classes: six functors formalisms, dualities, integrality and linear subspaces of complete intersections
We
equate various Euler classes of algebraic vector bundles, including those of
BargeMorel, KassW., DégliseJinKhan, and one suggested by M.J. Hopkins,
A. Raksit, and J.P. Serre. We establish integrality results for this Euler class,
and give formulas for local indices at isolated zeros, both in terms of
6functor formalism of coherent sheaves and as an explicit recipe in
commutative algebra of Scheja and Storch. As an application, we compute the
Euler classes associated to arithmetic counts of dplanes on complete
intersections in P^n in terms of topological Euler numbers over R and C. This
is joint work with Tom Bachmann 

KAHW02 
24th March 2020 16:00 to 17:00 
Burt Totaro 
CANCELLED The integral Hodge conjecture for 3folds of Kodaira dimension zero.
We prove the integral Hodge conjecture for all 3folds X
of
> Kodaira dimension zero with H^0(X, K_X) not zero.
> This generalizes earlier results of Voisin and
Grabowski.
> The assumption is sharp, in view of counterexamples
by Benoist and
> Ottem. We also prove similar results on the integral
Tate conjecture.
> For example, the integral Tate conjecture holds for
abelian 3folds in
> any characteristic.


KAHW02 
25th March 2020 10:00 to 11:00 
Vasudevan Srinivas 
CANCELLED Algebraic versus topological entropy for varieties over finite fields
For an automorphism (or endomorphism) of an algebraic
variety, we consider some properties of eigenvalues of the induced linear
transformation on ladic cohomology, motivated by some results from complex
dynamics, related to the notion of entropy. This is a report on joint work with
H'el`ene Esnault, and some subsequent work of K.
Shuddhodan.


KAHW02 
25th March 2020 11:30 to 12:30 
Wiesława Nizioł 
CANCELLED padic comparison theorems for rigid analytic spaces
Classical padic comparison theorems link padic etale cohomology of schemes over local fields of mixed characteristic with their de Rham cohomology preserving all the underlying structures. I will survey the recent work on analogs of these theorems for rigid analytic varieties.


KAHW02 
26th March 2020 09:00 to 10:00 
Simon Pepin lehalleur 
CANCELLED Exponential motives and the Fourier transform
Varieties equipped with a regular function admit
interesting "exponential" cohomology theories: rapid decay
cohomology, twisted de Rham cohomology in characteristic 0, twisted ladic
cohomology in positive characteristic. They exhibit motiviclike properties 
weights, a kind of Hodge filtration, a period isomorphism  but do not fit into
the classical theory of motives. Building on ideas of KontsevichSoibelman and
FresánJossen, we construct triangulated categories of exponential Voevodsky
motives equipped with functors realising exponential cohomology theories. More
generally, we associate to any "six operation formalism" an
exponential version. Unlike classical motivic sheaf theories, these exponential
sheaf theories come with a builtin FourierDeligne transform, which plays a
key role in the construction of exponential realisations. This is joint work in
progress with Javier Fresán and Martin Gallauer.


KAHW02 
26th March 2020 10:10 to 11:10 
Anand Sawant 
CANCELLED $\mathbb A^1$connected components of ruled surfaces
A conjecture of Morel asserts that the sheaf of $\mathbb A^1$connected components of a space is $\mathbb A^1$invariant. We will discuss how the sheaves of ``naive" as well as ``genuine" $\mathbb A^1$connected components of a smooth projective birationally ruled surface can be determined using purely algebrogeometric methods. We will discuss a proof of Morel's conjecture for a smooth projective surface birationally ruled over a curve of genus > 0 over an algebraically closed field of characteristic 0. If time permits, we will indicate why the naive and genuine $\mathbb A^1$connected components of such a birationally ruled surface do not coincide if the surface is not a minimal model and discuss some open questions and specultions regarding the situation in higher dimensions. The talk is based on joint work with Chetan Balwe.


KAHW02 
26th March 2020 11:30 to 12:30 
Toni Annala 
CANCELLED Derived Algebraic Cobordism
The purpose of this talk is to outline how to use derived algebraic geometry in order to give a very general geometric construction of algebraic cobordism in the spirit of Levine and Morel. The new construction requires no smoothness hypotheses on the variety, and works over a Noetherian ground ring of finite Krull dimension (as opposed over a field of characteristic 0). Moreover, the construction is naturally part of a larger bivariant theory in the sense of Fulton and MacPherson. We will outline what is known about derived cobordism theory. Most importantly: it has the expected relationship with the Grothendieck ring of vector bundles and satisfies projective bundle formula. 

KAHW02 
26th March 2020 14:30 to 15:30 
Nikita Semenov 
CANCELLED Hopftheoretic approach to motives of twisted flag varieties
Let G be a split semisimple algebraic group over a field and let A be an oriented cohomology theory in the sense of LevineMorel. We provide a uniform approach to the Amotives of geometrically cellular smooth projective Gvarieties based on the Hopf algebra structure of A(G). Using this approach we provide various applications to the structure of motives of twisted flag varieties. The talk is based on a joint work with Victor Petrov.


KAHW02 
26th March 2020 16:00 to 17:00 
Adeel Khan 
CANCELLED Chowtheoretic vs. Ktheoretic GromovWitten invariants
Let X be a smooth projective complex variety. We prove the comparison between the
GromovWitten invariants of X with their Ktheoretic variants defined by
Givental and Lee. The key ingredient is
a virtual GrothendieckRiemannRoch formula on the moduli stack of stable maps,
which is used to compare Kontsevich’s virtual fundamental class with the one
constructed by BehrendFantechi.


KAHW02 
27th March 2020 10:00 to 11:00 
Georg Tamme 
CANCELLED On a conjecture of Vorst
Quillen proved that algebraic Ktheory is A^1invariant on regular noetherian
schemes. Vorst’s conjecture is a partial converse. Let k be a field, and let A
be a kalgebra essentially of finite type and of dimension d. Vorst’s
conjecture predicts that if K_{d+1}(A) = K_{d+1}(A[t_1, \dots, t_m]) for all
positive integers m, then A is regular. This conjecture was proven by Cortinas,
Haesemeyer, and Weibel in case k has characteristic 0. In the talk, I will
explain the proof of a slightly weaker version of the conjecture if k has
positive characteristic. Joint work with Moritz Kerz and Florian Strunk. 

KAHW02 
27th March 2020 11:30 to 12:30 
Maria Yakerson 
CANCELLED Motivic generalized cohomology theories from framed perspective
All motivic generalized cohomology theories acquire
unique structure of so called framed transfers. If one takes framed transfers
into account, it turns out that many interesting cohomology theories can be
constructed simply as suspension spectra on certain moduli stacks (and their
variations). This way important cohomology theories on schemes get new
geometric interpretations, and so do canonical maps between different cohomology
theories. In the talk we will explain the general formalism of framed transfers
and show how it works for various cohomology theories. This is a summary of
joint projects with Tom Bachmann, Elden Elmanto, Marc Hoyois, Joachim
Jelisiejew, Adeel Khan, Denis Nardin and Vladimir Sosnilo.


KAHW02 
27th March 2020 13:30 to 14:00 
Free Time  
KAHW03 
30th March 2020 10:00 to 11:00 
Christopher Deninger  CANCELLED tba  
KAHW03 
30th March 2020 11:30 to 12:30 
Minhyong Kim 
CANCELLED Principal Bundle in Diophantine Geometry
This talk will give an update on the use of
nonabelian cohomology varieties in the theory of Diophantine equations 

KAHW03 
30th March 2020 15:00 to 16:00 
Matilde Lalín 
CANCELLED The Mahler measure of a genus 3 family
The Mahler measure of a polynomial P is defined as
certain integral of logP over the unit torus. For multivariate polynomials,
it often yields special values of Lfunctions. In this talk I will discuss some
of these relationships and prove an
identity between the Mahler measures of a genus 3 polynomial family and of a
genus 1 polynomial family that was initially conjectured by Liu and Qin. This
is joint work with Gang Wu.
