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* Re: Pieter Hofstra
@ 2022-05-03 20:48 JS PL
  2022-05-04 16:57 ` Joyal, André
  0 siblings, 1 reply; 10+ messages in thread
From: JS PL @ 2022-05-03 20:48 UTC (permalink / raw)
  To: Philip Scott; +Cc: categories

I am very sad about Pieter's passing.

I did my undergrad at the University of Ottawa, where Pieter was one of my
teachers and mentors.
I did my first research project with Pieter and Pieter was the one who
taught me category theory.

Over the years, I got to hangout with Pieter at numerous conferences and
seminars.
I got to work with Pieter and also become friends with him.
I always enjoyed having a chat with Pieter and going for food and drinks.

Pieter will be greatly missed. My condolences to his family and friends.

JS PL


On Wed, 4 May 2022 at 04:46, Philip Scott <scpsg@uottawa.ca> wrote:

> It is with great sadness that we announce that our dear friend and
> colleague Pieter Hofstra (1975-2022) passed away unexpectedly on May 1.
> Pieter obtained his PhD from Utrecht University, under Jaap van Oosten,
> studying realizability toposes. His research interests included general
> topos theory, realizability, inverse semigroups and groupoids, abstract
> computability, and homotopy type theory. Among his recent works, with J.
> Funk he introduced the notion of isotropy groups of toposes, which he was
> actively developing with students and colleagues.
>
> While Pieter was a brilliant researcher, a kind teacher and a caring
> supervisor, we will most remember him as a friend. When we have any
> details for a memorial service, we will pass them along.
>
> Richard Blute, Simon Henry, Philip Scott  (University of Ottawa)
>

[For admin and other information see: http://www.mta.ca/~cat-dist/ ]


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: Pieter Hofstra
  2022-05-03 20:48 Pieter Hofstra JS PL
@ 2022-05-04 16:57 ` Joyal, André
  0 siblings, 0 replies; 10+ messages in thread
From: Joyal, André @ 2022-05-04 16:57 UTC (permalink / raw)
  To: Philip Scott, JS PL; +Cc: categories

Dear Philip,


I am saddened and surprised to learn that Pieter Hoftras passed away.
It is unfair, he was still young!
He was a warm person and a talented mathematician!
His work combines geometric thinking with formal logic.
It is a great loss for the community of category theorists.
It was always a great pleasure to discuss with him.

My sincerere condolences to his family and friends.


Best regards,
André



On Wed, 4 May 2022 at 04:46, Philip Scott <scpsg@uottawa.ca> wrote:

> It is with great sadness that we announce that our dear friend and
> colleague Pieter Hofstra (1975-2022) passed away unexpectedly on May 1.
> Pieter obtained his PhD from Utrecht University, under Jaap van Oosten,
> studying realizability toposes. His research interests included general
> topos theory, realizability, inverse semigroups and groupoids, abstract
> computability, and homotopy type theory. Among his recent works, with J.
> Funk he introduced the notion of isotropy groups of toposes, which he was
> actively developing with students and colleagues.
>
> While Pieter was a brilliant researcher, a kind teacher and a caring
> supervisor, we will most remember him as a friend. When we have any
> details for a memorial service, we will pass them along.
>
> Richard Blute, Simon Henry, Philip Scott  (University of Ottawa)
>

[For admin and other information see: http://www.mta.ca/~cat-dist/ ]


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: Pieter Hofstra
@ 2022-06-01 10:38 Oosten, J. van (Jaap)
  0 siblings, 0 replies; 10+ messages in thread
From: Oosten, J. van (Jaap) @ 2022-06-01 10:38 UTC (permalink / raw)
  To: categories

Dear all,

I have also written up some memories of Pieter; they can be found at
https://webspace.science.uu.nl/~ooste110/hofstramemory.html

Best to all, Jaap
________________________________
Van: Eugenia Cheng <echeng4@saic.edu>
Verzonden: donderdag 5 mei 2022 18:10
Aan: Philip Scott <scpsg@uottawa.ca>; categories@mta.ca <categories@mta.ca>
Onderwerp: categories: Re: Pieter Hofstra

[U ontvangt vaak geen e-mail van echeng4@saic.edu. Informatie over waarom dit belangrijk is op https://aka.ms/LearnAboutSenderIdentification.]

I am devastated by the death of my dear friend and colleague
Pieter Hofstra.

Pieter was one of my closest friends in the world. It is one of the
extraordinary things about being a mathematician, that one becomes
close friends with people even without ever having lived in the same
place as them.

I met Pieter at the PSSL in Braunschweig in April 2000 when we were
both PhD students. It's particularly crucial to make friends at conferences
when you're a PhD student and new to everything, because it's all so
daunting. I rely heavily on surrounding myself with friends. Pieter was
one of the friends whom I relied on at conferences and also in all of life.
We became friends immediately, connecting over category theory,
Schubert, espresso, single malt whisky.

Pieter was the best friend I can imagine. He was always there for me
through the amazing ups and terrible downs of these last 22 years.
He had the sharpest perception, wriest wit, and the most exquisite
command of the English language despite it not being his first
language. He helped me understand category theory that I felt
stupid for not understanding, but he never made me feel stupid.
He gave beautiful talks, and taught me the amazing technique of
planning board talks actually board by board to ensure a good layout
of notes on the boards.

As Robin mentioned, Pieter was an accomplished poker player
and gave an extremely popular maths course on the maths of poker.
At the end of conferences we had a tradition of going to a casino
and spending the evening at a poker table. We would both put money
in, and then I'd watch as he calmly doubled or tripled it. I know nothing
about poker, but I enjoyed watching the other players trying, and failing,
to size him up.

At the Kananaskis workshop in 2006 we were halfway through a bottle
of Islay whisky when he offered me some more and said "More whisky,
Dear Colleague?" and for some reason we took to addressing each
other as Dear Colleague for ever more. It was a ridiculous moniker
for someone who was so much more than a colleague, but Pieter
was the master of understatement.

I miss my Dear Colleague terribly. I am devastated, and my life
will never be the same. My heart goes out to all those mourning
his loss.

Eugenia




On Tue, May 3, 2022 at 2:47 PM Philip Scott <scpsg@uottawa.ca> wrote:

> It is with great sadness that we announce that our dear friend and
> colleague Pieter Hofstra (1975-2022) passed away unexpectedly on May 1.
> Pieter obtained his PhD from Utrecht University, under Jaap van Oosten,
> studying realizability toposes. His research interests included general
> topos theory, realizability, inverse semigroups and groupoids, abstract
> computability, and homotopy type theory. Among his recent works, with J.
> Funk he introduced the notion of isotropy groups of toposes, which he was
> actively developing with students and colleagues.
>
> While Pieter was a brilliant researcher, a kind teacher and a caring
> supervisor, we will most remember him as a friend. When we have any
> details for a memorial service, we will pass them along.
>
> Richard Blute, Simon Henry, Philip Scott  (University of Ottawa)
>

[For admin and other information see: http://www.mta.ca/~cat-dist/ ]


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Pieter Hofstra
@ 2022-05-11 15:57 Thomas Fiore
  0 siblings, 0 replies; 10+ messages in thread
From: Thomas Fiore @ 2022-05-11 15:57 UTC (permalink / raw)
  To: categories net

  Dear Friends and Colleagues,

I send my condolences to all of Pieter's family, friends, and colleagues.

The news of his passing last week deeply affected me. Pieter and I were
postdocs around the same time, meeting occasionally at conferences, such as
Octoberfest and CTs. I felt a bond with him, being from the same
generation, and I think anyone who knew him felt a bond because of his
personality. He had such a beaming smile and patient, friendly, kind way of
explaining and discussing. The way he discussed mathematics was full of
youth. And so was he. I was so shocked and sad to read the news of his
passing. I just can't grasp it.

Sincerely,
Tom Fiore


[For admin and other information see: http://www.mta.ca/~cat-dist/ ]


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: Pieter Hofstra
@ 2022-05-05 16:10 Eugenia Cheng
  0 siblings, 0 replies; 10+ messages in thread
From: Eugenia Cheng @ 2022-05-05 16:10 UTC (permalink / raw)
  To: Philip Scott, categories

I am devastated by the death of my dear friend and colleague
Pieter Hofstra.

Pieter was one of my closest friends in the world. It is one of the
extraordinary things about being a mathematician, that one becomes
close friends with people even without ever having lived in the same
place as them.

I met Pieter at the PSSL in Braunschweig in April 2000 when we were
both PhD students. It's particularly crucial to make friends at conferences
when you're a PhD student and new to everything, because it's all so
daunting. I rely heavily on surrounding myself with friends. Pieter was
one of the friends whom I relied on at conferences and also in all of life.
We became friends immediately, connecting over category theory,
Schubert, espresso, single malt whisky.

Pieter was the best friend I can imagine. He was always there for me
through the amazing ups and terrible downs of these last 22 years.
He had the sharpest perception, wriest wit, and the most exquisite
command of the English language despite it not being his first
language. He helped me understand category theory that I felt
stupid for not understanding, but he never made me feel stupid.
He gave beautiful talks, and taught me the amazing technique of
planning board talks actually board by board to ensure a good layout
of notes on the boards.

As Robin mentioned, Pieter was an accomplished poker player
and gave an extremely popular maths course on the maths of poker.
At the end of conferences we had a tradition of going to a casino
and spending the evening at a poker table. We would both put money
in, and then I'd watch as he calmly doubled or tripled it. I know nothing
about poker, but I enjoyed watching the other players trying, and failing,
to size him up.

At the Kananaskis workshop in 2006 we were halfway through a bottle
of Islay whisky when he offered me some more and said "More whisky,
Dear Colleague?" and for some reason we took to addressing each
other as Dear Colleague for ever more. It was a ridiculous moniker
for someone who was so much more than a colleague, but Pieter
was the master of understatement.

I miss my Dear Colleague terribly. I am devastated, and my life
will never be the same. My heart goes out to all those mourning
his loss.

Eugenia




On Tue, May 3, 2022 at 2:47 PM Philip Scott <scpsg@uottawa.ca> wrote:

> It is with great sadness that we announce that our dear friend and
> colleague Pieter Hofstra (1975-2022) passed away unexpectedly on May 1.
> Pieter obtained his PhD from Utrecht University, under Jaap van Oosten,
> studying realizability toposes. His research interests included general
> topos theory, realizability, inverse semigroups and groupoids, abstract
> computability, and homotopy type theory. Among his recent works, with J.
> Funk he introduced the notion of isotropy groups of toposes, which he was
> actively developing with students and colleagues.
>
> While Pieter was a brilliant researcher, a kind teacher and a caring
> supervisor, we will most remember him as a friend. When we have any
> details for a memorial service, we will pass them along.
>
> Richard Blute, Simon Henry, Philip Scott  (University of Ottawa)
>
>

[For admin and other information see: http://www.mta.ca/~cat-dist/ ]


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: Pieter Hofstra
  2022-05-03 18:32 Philip Scott
  2022-05-04 15:58 ` Jon Sterling
@ 2022-05-04 21:11 ` Robin Cockett
  1 sibling, 0 replies; 10+ messages in thread
From: Robin Cockett @ 2022-05-04 21:11 UTC (permalink / raw)
  To: Philip Scott, categories net

This is very sad news indeed.   Pieter was a postdoc with me at Calgary 2005/6 before he moved (back) to Ottawa as a member of faculty.   While in Calgary he developed with me the theory of Turing categories (abstract computability).   Subsequently, we kept in touch and he was a frequent visitor at our home: I valued him not only as a colleague but also as a friend.

Pieter was very popular amongst the mathematicians at Calgary as he gave incredibly clear well-organized seminars on a wide variety of topics.  He was  also, for the same reason, a very popular teacher.

While at Calgary, Pieter supplemented his meager postdoc salary in a rather  unusual way.  He would play poker on-line.  He was incredibly disciplined about it ... and invariably walked away with a profit.   To him it all seemed very simple!   When he moved to Ottawa he started a course in gaming which I understand was very popular (although I rather doubt whether his students could bring the same discipline to it as Pieter).

I will miss him.

-robin
(Robin Cockett)
________________________________
From: Philip Scott <scpsg@uottawa.ca>
Sent: Tuesday, May 3, 2022 12:32 PM
To: categories@mta.ca <categories@mta.ca>
Cc: Philip Scott <philip.scott@uottawa.ca>
Subject: categories: Pieter Hofstra

[△EXTERNAL]



It is with great sadness that we announce that our dear friend and
colleague Pieter Hofstra (1975-2022) passed away unexpectedly on May 1.
Pieter obtained his PhD from Utrecht University, under Jaap van Oosten,
studying realizability toposes. His research interests included general
topos theory, realizability, inverse semigroups and groupoids, abstract
computability, and homotopy type theory. Among his recent works, with J.
Funk he introduced the notion of isotropy groups of toposes, which he was
actively developing with students and colleagues.

While Pieter was a brilliant researcher, a kind teacher and a caring
supervisor, we will most remember him as a friend. When we have any
details for a memorial service, we will pass them along.

Richard Blute, Simon Henry, Philip Scott  (University of Ottawa)


[For admin and other information see: http://www.mta.ca/~cat-dist/ ]


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: Pieter Hofstra
@ 2022-05-04 19:59 Matias M
  0 siblings, 0 replies; 10+ messages in thread
From: Matias M @ 2022-05-04 19:59 UTC (permalink / raw)
  To: categories

What an awful piece of news.

During his PhD, Pieter visited Genova while I was there and he shared a
flat above mine in the old town. He was not only a good neighbor but he
also became a good friend indeed. If I remember correctly, he had a degree
in Philosophy. His conversation was kind, clever and entertaining. We did
not always agree on academic matters but I always tried to meet with him
during the ct's to talk and recall our days in Italy under Pino's
protection. Last time was at the Bow Bar in Edinburgh where we talked about
his work with Jon and about how much he enjoyed being a father.

M.



> ---------- Forwarded message ---------
> De: Philip Scott <scpsg@uottawa.ca>
> Date: mar., 3 de mayo de 2022 2:46 p. m.
> Subject: categories: Pieter Hofstra
> To: categories@mta.ca <categories@mta.ca>
> Cc: Philip Scott <philip.scott@uottawa.ca>
>
>
> It is with great sadness that we announce that our dear friend and
> colleague Pieter Hofstra (1975-2022) passed away unexpectedly on May 1.
> Pieter obtained his PhD from Utrecht University, under Jaap van Oosten,
> studying realizability toposes. His research interests included general
> topos theory, realizability, inverse semigroups and groupoids, abstract
> computability, and homotopy type theory. Among his recent works, with J.
> Funk he introduced the notion of isotropy groups of toposes, which he was
> actively developing with students and colleagues.
>
> While Pieter was a brilliant researcher, a kind teacher and a caring
> supervisor, we will most remember him as a friend. When we have any
> details for a memorial service, we will pass them along.
>
> Richard Blute, Simon Henry, Philip Scott  (University of Ottawa)
>

[For admin and other information see: http://www.mta.ca/~cat-dist/ ]


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: Pieter Hofstra
@ 2022-05-04 17:49 Jason Parker
  0 siblings, 0 replies; 10+ messages in thread
From: Jason Parker @ 2022-05-04 17:49 UTC (permalink / raw)
  To: categories

I am deeply saddened by Pieter's passing.

Pieter was one of my PhD advisors (along with Philip Scott) at the
University of Ottawa from 2015-2020. I was also a TA for some of his
classes on a few occasions. He was always very kind, respectful, and
generous with his time and energy, and he was an insightful and encouraging
teacher, mentor, and advisor. He had an immense impact on my development
both as a mathematician and as a person.

He will be deeply missed. I also send my condolences to his family,
friends, and colleagues.

-Jason Parker

On Tue, May 3, 2022 at 2:46 PM Philip Scott <scpsg@uottawa.ca> wrote:

> It is with great sadness that we announce that our dear friend and
> colleague Pieter Hofstra (1975-2022) passed away unexpectedly on May 1.
> Pieter obtained his PhD from Utrecht University, under Jaap van Oosten,
> studying realizability toposes. His research interests included general
> topos theory, realizability, inverse semigroups and groupoids, abstract
> computability, and homotopy type theory. Among his recent works, with J.
> Funk he introduced the notion of isotropy groups of toposes, which he was
> actively developing with students and colleagues.
>
> While Pieter was a brilliant researcher, a kind teacher and a caring
> supervisor, we will most remember him as a friend. When we have any
> details for a memorial service, we will pass them along.
>
> Richard Blute, Simon Henry, Philip Scott  (University of Ottawa)
>

[For admin and other information see: http://www.mta.ca/~cat-dist/ ]


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: Pieter Hofstra
  2022-05-03 18:32 Philip Scott
@ 2022-05-04 15:58 ` Jon Sterling
  2022-05-04 21:11 ` Robin Cockett
  1 sibling, 0 replies; 10+ messages in thread
From: Jon Sterling @ 2022-05-04 15:58 UTC (permalink / raw)
  To: Philip Scott; +Cc: categories

I've been thinking about Pieter all day. He spent some months with us at Carnegie Mellon visiting Steve Awodey during the early stages of my PhD. During that time he taught me a lot, and also gave me some sage advice at a time when I needed it. I will miss the kind and generous way that he would explain things, and I am shaken that I will never get to talk with him again.

My condolences to his family and close friends, and to the category theory community as a whole. This is a great loss.

Sincerely,
Jon



> On May 3, 2022, at 8:32 PM, Philip Scott <scpsg@uottawa.ca> wrote:
> 
> It is with great sadness that we announce that our dear friend and
> colleague Pieter Hofstra (1975-2022) passed away unexpectedly on May 1.
> Pieter obtained his PhD from Utrecht University, under Jaap van Oosten,
> studying realizability toposes. His research interests included general
> topos theory, realizability, inverse semigroups and groupoids, abstract
> computability, and homotopy type theory. Among his recent works, with J.
> Funk he introduced the notion of isotropy groups of toposes, which he was
> actively developing with students and colleagues.
> 
> While Pieter was a brilliant researcher, a kind teacher and a caring
> supervisor, we will most remember him as a friend. When we have any
> details for a memorial service, we will pass them along.
> 
> Richard Blute, Simon Henry, Philip Scott  (University of Ottawa)
> 
> 
> [For admin and other information see: http://www.mta.ca/~cat-dist/ ]



[For admin and other information see: http://www.mta.ca/~cat-dist/ ]


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Pieter Hofstra
@ 2022-05-03 18:32 Philip Scott
  2022-05-04 15:58 ` Jon Sterling
  2022-05-04 21:11 ` Robin Cockett
  0 siblings, 2 replies; 10+ messages in thread
From: Philip Scott @ 2022-05-03 18:32 UTC (permalink / raw)
  To: categories; +Cc: Philip Scott

It is with great sadness that we announce that our dear friend and
colleague Pieter Hofstra (1975-2022) passed away unexpectedly on May 1.
Pieter obtained his PhD from Utrecht University, under Jaap van Oosten,
studying realizability toposes. His research interests included general
topos theory, realizability, inverse semigroups and groupoids, abstract
computability, and homotopy type theory. Among his recent works, with J.
Funk he introduced the notion of isotropy groups of toposes, which he was
actively developing with students and colleagues.

While Pieter was a brilliant researcher, a kind teacher and a caring
supervisor, we will most remember him as a friend. When we have any
details for a memorial service, we will pass them along.

Richard Blute, Simon Henry, Philip Scott  (University of Ottawa)


[For admin and other information see: http://www.mta.ca/~cat-dist/ ]


^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2022-06-01 10:38 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-05-03 20:48 Pieter Hofstra JS PL
2022-05-04 16:57 ` Joyal, André
  -- strict thread matches above, loose matches on Subject: below --
2022-06-01 10:38 Oosten, J. van (Jaap)
2022-05-11 15:57 Thomas Fiore
2022-05-05 16:10 Eugenia Cheng
2022-05-04 19:59 Matias M
2022-05-04 17:49 Jason Parker
2022-05-03 18:32 Philip Scott
2022-05-04 15:58 ` Jon Sterling
2022-05-04 21:11 ` Robin Cockett

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