I want to express my sincere condolences to
Victor's wife and his family and his passing.
It's a great loss for them, his colleagues,
Wichita State and all of the inverse problems community worldwide.
I became aware of Victor's work in the
late 80s when I was sent by a
leading journal, one of his papers to referee.
I immediately realized that the author,
whom I didn't know, was an
original mathematician, the first mathematician.
The paper had a very nice and beautiful idea.
I had the privilege of meeting Victor personally for
the first time when I visited him in 1990.
He was extremely gracious host at that time.
He was working on his book called Inverse Problems for Partial
Differential Equations is the technical name that became a classic
in the field in the next 30 years.
We met many times at conferences and
also in visits to Wichita State.
We talked many times.
We only collaborated with one paper,
but I appreciate it very much.
His original thinking.
He had very nice ideas.
He made great contributions to our field.
The most important.
He was always very generous, kind,
especially with the young people.
He will be solely missed.
Good-bye, my friend.
Rest in peace.
Hello, my name is John Sylvester.
Victor and I have been friends for over 30 years.
We first met in 1987, when we were
both visiting the Courant Institute for a semester.
From the beginning, I found Victor to be humble,
always easy to talk to and always willing to
explain something, even if it took two or even
three different explanations before I finally understood.
That attitude never changed, even as it became
more well known and his accomplishments grew.
In the past decades.
We met mostly at conferences and would
frequently take long walks, sometimes for several
hours discussing whatever came to mind.
I always sought Victor's advice about difficult editorial
decisions, and he was always happy to help.
I think of Victor not so much as a colleague, but more
of more as a good friend, and I will miss him.
Hello, everyone.
I treasure the memories of
all my interactions with Victor.
He was a real gentleman.
He loved mathematics, he had an extensive knowledge of
PEs, and I learned a lot from him.
He was excited, especially about new ideas,
and contributed many original ones over the
course of an impressive career.
He was open and a pleasure to talk to.
We also shared a love of music,
where he had equally high standards.
I remember with fondness when Victor and Julie visited
us about 20 years ago, and we spent the
whole evening listening to recordings of great pianists, in
particular Sviatoslav Richter, whom Victor and I both loved.
I then tried to slip in a piece with a slightly less
known pianist whom I was fond of, and I remember Victor looking
at me and saying, Why did you play that one?
But he was very proud of Julie's playing, and he sent me
a CD of a recycle of hers, which I still have.
Victor, may your memory be a blessing.
For those who don't know me.
I am Lassi Päivärinta from
Tallinn University of Technology.
In this memory a tribute of Victor Mikhailovich Isakov.
I memorize him as a colleague
and friend, but also as inspiration.
I met him first time nearly 30 years
ago in the Lapland Conference on Inverse Problems.
My first impression on him was
that he was fearless and friendly.
He could not betray anyone as a thinker.
He was, more than anything, deep
both in mathematics and in culture.
In 1995 I visited Wichita and I stayed in his house
during long evenings we discussed mathematics, not only
about inverse problems, but in general he played
his grand piano and Crime and Punishment were
there, at least in discussed literature.
For the Russian-Finnish friendship
we finished several bottles of vodka.
Ziki Sun's email carrying the news from Victor's
passing arrived to me on May 31.
I read it the next day in the afternoon at 05:00 p.m.
My thought went to Andalusian poet Federico
García Lorca and to his poem Lament for
Death of Bullfighter Llanto por Ignacio Sánchez Mejías.
Mejías was a personal friend of Lorca.
"In the afternoon.
It was exactly five in the afternoon.
A boy brought a white sheet.
At five in the afternoon, a frail of
lime ready preserved at five in the afternoon. A las cinco de la tarde. Eran las cinco en punto de la tarde. Un niño trajo la blanca sábana a las cinco de la tarde. Una espuerta de cal ya prevenida a las cinco de la tarde. Lo demás era muerte y sólo muerte a las cinco de la tarde".
Farewell, Victor, and rest in peace.
My name is Bill Rundell, and I'm glad
to be able to speak at this funeral.
I've known Victor for well over 30 years, and
I always look forward to meeting you at conferences.
I like to tell you one story
about such a conference 25 years ago.
Oberwolfach.
In those days the convention was to have a
musical evening, typically after the walk on Wednesday.
Downstairs in the basement, there was
violins, violas, cellos, and a Steinway.
Victor was, of course, in his element, and the
audience egged him on, wouldn't let him stop.
And one seasoned observer of these things himself, an
accomplished musician, said, this is by far the best
musical evening you'd ever seen at all.
Well there was other reasons, too,
why I wanted to meet Victor. At meetings.
I would store up questions for them that
were puzzled for me, and often Victor would
say, that's going to be hard.
But that was good, because that meant
that problem could be chopped off
my to do list.
Victor was a wonderful human being.
Everyone liked him, and everyone liked him
for a very, very good reason.
He was kind, he liked people, and he loved mathematics.
He was actually utterly sensible.
Well, except for one thing.
His penchant during talks for making his slides
out of a bad photocopy of his latest paper.
But the content was always there.
And people, of course, forgave him.
It's hard to say much more without
going on and on and on.
But Victor is gone.
But his work, in particular his
books, will always be with us.
Thank you.
I am most profoundly grateful for the opportunity to
say a few words about Professor Victor Isakov.
Back in 2011, when I was working as
an Academy Research Fellow at the University of
Helsinki, Finland, I become extremely fascinated with a
very interesting and deep paper by Professor Victor
Isakov on uniqueness in general in transmission problem.
So this paper was published in
Communications in Mathematical Physics in 2008.
And here you can see the
first page of this remarkable paper.
Following one of the suggestions made by Professor Isakov
in his work, I have decided to attempt to
extend the analysis to the case of Schrödinger
operators in the presence of magnetic field.
While working on this project, I have received a
lot of invaluable advice and encouragement from Professor Isakov,
which has been absolutely crucial for my work.
This work would, in fact, never have been
completed without Professor Isakov extremely invaluable help.
In May of 2016, I had the great pleasure
of meeting and talking to Professor Isakov in the
workshop on Dirichlet-to-Neumann Maps, Spectral Theory in those Problems
and application which held at Oaxaca, Mexico.
And here you can see the picture from this workshop.
Let me zoom it a little bit so you can
see Victor Isakov among the participants of this workshop.
I remember distantly the very beautiful talk given
by Professor Isakov for this meeting which was
devoted to the problem of increasing stability in
inverse problems at high frequency.
And luckily we can still watch the video, rewatch
the video of his talk at the webpage.
So this is the video of Victor's talk and
let us just watch it for a minute.
But this one common ground: Eigen functions.
But in inverse problems, one
of crucial issues is stability.
Stability means that how much your. It is really
incredibly important talk for me and the topic which
Victor's talk is very influential for my research.
As recently as March 18 this year, Professor Isakov
gave a brilliant talk at our international Zoom Inverse
Problems seminar which we have been organizing jointly with
Knut Solna during the Pandemic time.
And luckily we have a video of his talk which is
available on our YouTube channel and in our seminar web page.
So the issue is topic is increasing stability.
So there are two parts of it.
First of all, is that one of bigger so.
So it's extremely beautiful lecture and it is very sad
and indeed shocking to think that this might have
been the very last talk that he gave.
The work by Professor Isakov had truly a most
profound and lasting effect on me and I am
convinced that it will continue to play a fundamental
role in the entire inverse community, educating and expiring
the new generations of researchers.
I would like to express my most part well.
Sincerely condolences.
I am Masahiro Yamamoto from the University of Tokyo.
I am so sorry and sad that Victor passed away.
I sincerely send my deepest
condolence, especially for Julie.
Please let me convey my heartiest
sympathies. For the first time.
I met Victor in 1989, more
than 40 years ago in California.
Since then I have shared the mathematical life
and also as a cultural interest with him.
I have attended with him many conferences in Oberwolfach,
Garda Lake in Lombardia and Catania in Sicily and
Texas and Shanghai, et cetera, and also the General
board of meetings in London every year.
Also, many times we meet in Japan.
This is my great pleasure many times
and we could enjoy mathematics and talks.
Also music.
He likes a especially
Russian composer Sergei Rachmaninoff.
As many know, he played the piano very
well and did so, for example at the
music room of Mathematics Institute in Oberwolfach.
I can have many nice memories for spending nice
times and beautiful places and also mathematical discussions.
Sometimes mathematical discussions were
rather hard and serious. Of course.
Needless to say, he is a distinguished expert for
inverse problems and made a lot of academic contribution.
Victor, I thank you so much for
the long standing friendship and reaching definitely
my life. May he rest in peace.
I am praying for Julie and his
family for overcoming this deepest sorrow.
Thank you very much.
My thoughts are always with you.
I'm Jin Cheng from Fudan University at Shanghai, China.
I was deeply saddened when
I learned about Victor passing.
We lost an esteemed leader
in the inverse problem community.
I know Professor Isakov's name when I was visiting Professor
Engel in Adelaide, Australia as a possible doctor fellow.
Professor Engel showed me his joint paper with Victor and
told me some story about Victor and his research.
After reading their papers on the uniqueness of
an inverse problem for partial differential equations, I
finished my first paper on inverse problems.
I first met Victor in the international
conference in Kyoto University of Japan.
After his talk, we shortly discussed some problems.
Victor is a genius for inverse problem
and he has made several essential contributions
on some difficulty inverse plan.
He always had some original idea
for the difficulty inverse form.
With Victor, I have discussed some interesting inverse form and
he can always catch the key points and propose the
new ideas and method to solve this problem.
Once we organize an international conference in
Shanghai to celebrate his 60th birthday, he
visited Shanghai several times and we share
the enjoyable time in our Compass.
I believe that Victor will be remembered forever
by participating in the inverse from community.
Thank you for coming to celebrate life
and share our growth as passion.
My name is Jianliang Qian.
I'm professor at Michigan State University.
I have known Victor's name through
his book on inverse problems.
From 2005 to 2007, I have spent two years
at Wichita State University as Assistant Professor.
During that time period, I had the
fortune to interact with Victor frequently.
I have learned a lot about him on many research topics.
In particular, I have learned from
him on inverse gravity problems.
Along that line, we even written two papers together.
Based on those works, I have developed
a research program on computational gravity problems.
Therefore, I appreciate his generosity and
his willingness to help others.
I'm sure he will be
remembered by our research community.
I will miss him very much.
I'm Mikhail Klibanov.
I'm university colleague, I would say, and
I would say good friend of Mr.
Victor Isakov.
And even though today is June 1 2021 and Victor died on May
14, I still cannot believe that he died. In my heart
he's alive and he's a young boy.
I knew Victor for sure must say entire life. When I was a student at Novosibirsk University, in Novosibirsk, Russia, his thesis advisor, Professor Aleksey Ivanovich Prilepko
was giving us a course in complex analysis
and I remember Aleksey Ivanovich very proud.
He said my great graduate student.
Victor got a great result, and we young boys
and girls were very excited by these words.
Since then, I took an example of great research.
At that time, I did not know what these problems
are, frankly, but when I became graduate and we knew
each other in Russia, we still kept our friendship.
In the United States, we work in different
universities and not seeing each other, not communicating.
But we respected each other so
much on a very high level.
So farewell, Victor.
You are still alive and young in my heart.
My name is Roberto Triggiani, and I'm delivering these
words also on behalf of my wife, Irena Lasiecka.
When my wife, Irena Lasiecka, and I received a
email in mid May from the former PhD student
Matthew Eller, with the totally unexpected news that Victor
Isakov had passed away two days before, it was
truly a painful and earthshaking shock of disbelief.
Our colleague and friend of so many years with
whom we have shared so many memorable moments.
Though it was in a common profession that
first brought us together many years ago, we
had since shared the deep personal and professional
respect combined with the warm sense of friendship.
Over the years we met at math conferences in
US, but even more frequently abroad Italy, Poland, sometime
with his wife, Julie, and we always found a
way to enjoy a dinner together to discuss professional
and more broad topics, including, of course, music.
We knew of several years of suffering before
1989 and had tremendous respect for him
for his most courageous stance.
Victor was a person of high principle,
high moral standards and great humanity.
Who those standards and those principles enacted
in his own personal and professional life.
I shall always treasure the two evenings I spent the
Julie's and Vicor's home in Wichita several years ago when I
was invited by him to give a colloquium talk.
First you enter their home and there you find
a grand piano on the left and a grand
piano on the right of the entrance.
What a remarkable couple.
Those evenings were, of course, filled with the
piano music and also videos of world class
pianists comparing the very different body styles while
playing between, say, Sviatoslav Richter and Arturo Benedetti.
Michelangeli.
The visit to Wichita was also critically important
for me professionally as it spurred me to
move into the area of inverse theory of
PDEs where he was an undisputed world leader.
We were frequently exchanging emails regarding professional
issue till a few months ago.
We shall dearly miss him.
We wish to offer to his wife, Julie
our deep condolences in the hope that our
genuine appreciation of Victor may soothe the family
grief and help preserve his memory.
I first met Professor Isakov shortly after I
arrived in the United States in 2000.
Of course, I knew his influential work in inverse
problems, his Springer book on inverse problems for PDEs.
Then the first edition was already on my
desk and his beautiful, uniqueness proof using singular
solutions had already inspired the entire area of
sampling methods for solving inverse scattering problems.
But meeting Professor Isakov in person while still
being a junior researcher, just to realize that
this big name in mathematics is most humble,
soft spoken, respectful and supportive person gave me
a great sense of encouragement and delight.
Passing of Professor Isakov is a
huge loss for our community.
His legacy as brilliant
mathematician will live forever.
Professor Isakov will always be remembered
as an inspiring teacher, a dear
colleague and an exceptional human being.
I'm Jenn-Nan Wang from Taiwan.
I'd like to take this opportunity
to pay my respects to Victor.
I met Victor in MSI in 2001.
At that time I was a postdoc in MSI.
We both were participants in
the program on inverse problems.
During that time I was stuck on a
question related to the current estimates and Victor
was an expert on his topic.
One day I visited his office and was kind of nervous.
Victor greeted me with enthusiasm.
I explained my question to him.
It didn't take too long for Victor
to come up with a possible solution.
I was able to solve the question with Victor's help.
We then published our first paper together.
Afterwards, we became long term cooperators.
We had worked on several issues on inverse
problems, especially on the increase in stability phenomena
for which Victor was truly a pioneer.
A trailblazer.
I feel so lucky to be able to
work with Victor for almost 20 years.
I also consider working with Victor a privilege.
He was a great mentor and was always
willing to share his ideas with others.
Victor, your profound contribution to the development
of inverse problems will be always remembered.
Rest in peace.