You are cordially invited to our next Monday Lecture in the New
Year. Next Monday Lecture, there will be again a regular schedule.

You may find valid Invitation for zoom throughout all winter term
here:

http://www.facetsofcomplexity.de/monday/WS-2020-21/index.html

Invitation link:

https://tu-berlin.zoom.us/j/69716124232?pwd=dzFlcTFHMmFXRTE5QmZLaEV5N0FRUT09

Monday Lecture will be on **January 11th 2021** at 14:15 h
& 16:00.

Zoom - Invitation

__Time__: **Monday, January 11th - 14:15 h**

__Lecture__: Raman Sanyal (Goethe-Universität Frankfurt)

__Title__: From counting lattice points to counting free
segments and back

__Time__: **Monday, ****January 11th -** 16:00
h

__Lecture__: Maria Dostert (Royal Institute of Technology)

__Title__: Exact semidefinite programming bounds for
packing problems

You are cordially invited to our next Monday Lecture in the New
Year.

You may find valid Invitation for zoom throughout all winter
term here:

http://www.facetsofcomplexity.de/monday/WS-2020-21/index.html

Invitation link:

https://tu-berlin.zoom.us/j/69716124232?pwd=dzFlcTFHMmFXRTE5QmZLaEV5N0FRUT09

Monday Lecture will be on **January 18th 2021** at 14:15 h
& 16:00.

Zoom - Invitation

__Time__: **Monday, January 18th - 14:15 h**

__Lecture__: Florian Frick (Carnegie Mellon University)

__Title__: New applications of the Borsuk--Ulam theorem

__Time__: **Monday, ****January 18th -**
16:00 h

__Lecture__: Pavle Blagojević (Freie Universität Berlin)

__Title__: Ten years in one lecture

We will see how

-- work on the Bárány-Larman conjecture on colored point sets in the plane gave birth to the Optimal colored Tverberg theorem,

-- the constraint method collected all classical Tverberg type results under one roof and opened a door towards counter-examples to the topological Tverberg conjecture.

Furthermore, we will illustrate how the search for convex
partitions of a polygon into pieces of equal area and equal
perimeter forced us to

-- study the topology of the classical configuration spaces,

-- construct equivariant cellular models for them,

-- prove a new version of an equivariant Goresky-MacPherson formula for complements of arrangements,

-- revisit a classical vanishing theorem of Frederick Cohen, and explain why these answers are related to the existence of highly regular embeddings and periodic billiard trajectories.

Finally, we will talk about

-- equi-partitions of convex bodies by affine hyperplanes, and

-- greedy convex partitions of many measures.

These results are joint work with, in chronological order, Günter M. Ziegler, Benjamin Matschke, Florian Frick, Albert Haase, Nevena Palić, Günter Rote, and Johanna K. Steinmeyer.

You are cordially invited to our next Monday Lecture. Next Monday
Lecture, there will be again the hearing of our
next PhD candidates.

We will have** two talks** this time. Talks will be 30 min. 15
min discussions, 15 min break.

All Monday Lectures and Colloquia of winter term 2020/21 will be
given online via zoom.

You may find valid Invitation for zoom throughout all winter term
here:

http://www.facetsofcomplexity.de/monday/WS-2020-21/index.html

Invitation link:

https://tu-berlin.zoom.us/j/69716124232?pwd=dzFlcTFHMmFXRTE5QmZLaEV5N0FRUT09

Monday Lecture will be on **January 25th 2021** at **14:15
h & 15:00** !

Zoom - Invitation

__Time__: **Monday, January 25th - 14:15 h**

__Lecture__: Michaela Borzechowski

__Title__: One-Permutation-Discrete-Contraction is
UEOPL-hard

UEOPL captures problems that have either by definition a unique solution, like the Arrival problem, or that are promised to have a unique solution by some property, like the P-Matrix linear complementary problem.

Furthermore the problems in UEOPL have the property that the candidate solutions can be interpreted as an exponentially large graph which form a line, i.e. each node has in and out degree at most 1. The solution of each problem is at the end of that line.

In 2017, Daskalakis, Tzamos and Zampetakis proved the problem of finding a fixpoint of a contraction map in a continuous space whose existence is guaranteed by the Banach fixed point theorem to be CLS-complete.

A discrete version of the contraction problem, called One-Permutation-Discrete-Contraction, is proven to be the first UEOPL-complete problem.

This proof is particularly interesting because it is currently the only one of its kind and lays the groundwork for future UEOPL-completeness proofs.

This talk will provide an overview of the reduction from the problem Unique-End-of-Potential-Line to One-Permutation-Discrete-Contraction as well as correcting some errors that were done in the original paper.

__Time__: **Monday, ****January 25th -** 15:00
h

__Lecture__: Shubhang Mittal

__Title__: tba

--------------933F1EA01D758D5D6CCE2D5E-- From itabrunke@zedat.fu-berlin.de Sun Jan 31 22:16:32 2021 Received: from outpost1.zedat.fu-berlin.de ([130.133.4.66]) by list1.zedat.fu-berlin.de (Exim 4.94) for facets-of-complexity@lists.fu-berlin.de with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (envelope-from

there will be

Next Monday Lecture will be on Monday, February 8th 2021 - to be announced as usual.

All the best,

Ita.

--------------D9F4E2A912B49A8E1E64AC9F-- From itabrunke@zedat.fu-berlin.de Wed Feb 03 16:18:20 2021 Received: from outpost1.zedat.fu-berlin.de ([130.133.4.66]) by list1.zedat.fu-berlin.de (Exim 4.94) for facets-of-complexity@lists.fu-berlin.de with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (envelope-from

You are cordially invited to our next Monday Lecture. Next Monday
Lecture, there will again be the hearing of one of our PhD
candidates.

We will have** one talk** this time only. Talk will be 30 min.
15 min discussion.

All Monday Lectures and Colloquia of winter term 2020/21 will be
given online via zoom.

http://www.facetsofcomplexity.de/monday/WS-2020-21/index.html

Invitation link:

https://tu-berlin.zoom.us/j/69716124232?pwd=dzFlcTFHMmFXRTE5QmZLaEV5N0FRUT09

Monday Lecture will be on **February 8th 2021** at **14:15
h** !

Zoom - Invitation

__Time__: **Monday, February 8th - 14:15 h**

__Lecture__: Helena Bergold (Fern Universität Hagen)

__Title__: Topological Drawings meet Classical Theorems of
Convex Geometry

--------------D07852352722F1F5E5CE4E2D-- From itabrunke@zedat.fu-berlin.de Wed Feb 17 15:29:15 2021 Received: from outpost1.zedat.fu-berlin.de ([130.133.4.66]) by list1.zedat.fu-berlin.de (Exim 4.94) for facets-of-complexity@lists.fu-berlin.de with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (envelope-from

You are cordially invited to our **last** Monday Lecture and
Colloquium of winter term 2020/21.

http://www.facetsofcomplexity.de/monday/WS-2020-21/index.html

Invitation link:

https://tu-berlin.zoom.us/j/69716124232?pwd=dzFlcTFHMmFXRTE5QmZLaEV5N0FRUT09

Monday Lecture and Colloquium will be on **February 22nd 2021**
at **14:15 h** and **16:00 h** s.t. !

Zoom - Invitation

__Time__: **Monday, February 22nd - 14:15 h**

__Lecture__: Peter Bürgisser (Technische Universität Berlin)

__Title__: Optimization, Complexity and Invariant Theory

__Time__: **Monday, February 22nd - 16:00 h s.t.**

__Colloquium__: Joanna Lada (Merton College Oxford)

__Title__: On colour-bias Hamilton cycles in dense graphs

--------------47C739CA1B4824F3C216A140-- From itabrunke@zedat.fu-berlin.de Mon Mar 29 16:52:29 2021 Received: from outpost1.zedat.fu-berlin.de ([130.133.4.66]) by list1.zedat.fu-berlin.de (Exim 4.94) for facets-of-complexity@lists.fu-berlin.de with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (envelope-from

this week we do have application talks again for 'Facets of Complexity', like we did in December and January.

You all are cordially invited. Schedule will be as given below:

14:00 Kunz Pascal 14:00 Karl Stickler

15:00 Vera Chekan 15:00 Alexandre Simon

16:00 Krishnendu Bhowmick

Schedule is: 30min talk, 15min discussion, 15 min break.

The talks will be over Zoom:

No password is needed.

Best regards,

Ita.

-- Graduiertenkolleg 'Facets of Complexity' Koordinatorin: Ita Brunke Raum 111 Tel.:838-52683 Freie Universität Berlin Institut für Informatik Takustr. 9 14195 Berlin (Dahlem)--------------18823F3241D9C25781C9CBBF--