Memorial to Professor Siegfried Schaible

Professor Siegfried Schaible (August 18, 1940 – September 7, 2014)


Professor Siegfried Schaible died on September 7, 2014 at the age of 74. Siegfried was born to Karl and Lina Schaible in Marburg, Germany during WWII. After high school graduation, he attended the University of Mainz where he met his future wife, Ingrid. They married in 1967. Siegfried studied mathematics and physics and finished two PhDs at the University of Cologne. In 1979 Siegfried took his wife and three kids and immigrated to Canada where he taught at the University of Alberta in Edmonton, Alberta. In 1987 he took a full-time tenured position at the Anderson Graduate School of Management at UC Riverside in California. In addition, he spent many years traveling and teaching at universities all over the world. He wrote for and edited many scientific journals and books in his field of expertise “Generalized Convexity.” In his spare time Siegfried enjoyed reading theology, taking pictures, playing the violin and exploring the outdoors. Siegfried was a widower for 11 years. After his retirement from UCR in 2006, he moved to Taiwan to teach at Chung Yuan Christian University.  He is survived by his siblings in Germany Dieter Schaible and Waltraut Kippenberger; his daughter and son-in-law Sue and Frank Suranyi of Camarillo, CA; his grandchildren Hannah, Joel, Elyse, Emme and Isabelle; his son and daughter-in-law John and Christy Schaible of Santa Ana, CA; his grandchildren Cody and Serena; and his daughter Rickie Schaible of Poway, CA. He will be missed by us all.

His family

1. Announcement to WGGC members

Dear members of WGGC,

On behalf of the Scientific Committee of our group, I am very sorry to announce the sad news that Siegfried Schaible, the founder of our group, passed away the morning of September 7.

Siegfried is dearly remembered by many members of our group. Not only for his major contributions to the topics of generalized convexity and generalized monotonicity, but also because of the special traits that made his personality so warm and unique.

Siegfried attended all international symposia on generalized convexity, starting from the first one in Vancouver, Canada, back in 1980; the only exception was the last one, a couple of weeks ago, which he did not attend due to his health problems. During all these years, he was the main driving force of the group; he devoted most of his energy and his time to the benefit of the group. He always insisted in the necessity to avoid exclusions, by ensuring a good geographical distribution and promoting diversity in the topics studied.

He had more than 60 coauthors during his long scientific career. I was one of them; actually, it was he who introduced me to generalized convexity, generalized monotonicity, variational inequalities, and many other fields in optimization. I will always be grateful to him for his guidance and friendship. I am sure that many others feel the same.

The Scientific Committee will honor the memory of Siegfried Schaible in various opportunities. As a first step, we created a memorial page where the members who wish to express their thoughts and condolences may do so:

If you would like to post a contribution in this page, please send a message to or just reply to this message. Your contribution will appear in 1-2 days.

Nicolas Hadjisavvas  (12/9/2014)

2. Message of Boris Mordukhovich, chair of WGCC

It is with great sadness that we heard the loss of Professor Siegfried Schaible. He was one of the pioneers of Generalized Convexity and Generalized Monotonicity. He created our group, and collaborated with many of its members. He will be remembered for his energy and devotion to the group, and also for his friendly manner towards all of us.

With my sincere condolences to his family,

Boris Mordukhovich (13/9/2014)

3. I was sorry and grieved to hear that Siegfried passed away.

I was deeply shocked by the sudden death of him.

He gave me several suggestions and advices with many mathematical sounds.

There are his great contributions to the progress in optimization especially generalized convexity, generalized monotonicity, variational inequalities. Moreover, he sent me warm messages concerning my health several times. He also accepted and used his Chinese name which was proposed by Prof. Hang-Chin Lai and myself in a taxi long time ago.

We remember forever his personality and activity.

Tamaki Tamaka (13/9/2014)

4. I am deeply saddened to learn about the passing of our Honor Chair, Professor Siegfried Schaible, a dear friend and collaborator for many of us.

We share his family’s grief in this time of bereavement with deepest sympathy and condolence.

Dinh The Luc (13/9/2014)

5. Please accept my deepest sincere condolence on the death of Siegfried Schaible.

Xun-Hua Gong (13/9/2014)

6.  I’m really sorry and sad to learn this bad news. Siegfried was indeed a really nice man, I have lot’s of pleasant things to remember him. Since I was nor able (unfortunately) to attend the meeting in Rio, I was just thinking whether he could participate…

At this moment I have in mind a nice episode related to Siegfried. It was in 1996 in Marseille, till then the symposium held each four years (if I’m not wrong: the site doesn’t work by this moment, I don’t know why, so I cannot check) and starting from then the period reduced to three years. Any time when a session ended, the chair said (as usual): “now we take a coffee break”. After the last, closing session Siegfried said: “now we take a coffee break of three years!”…the next symposium was planned in Samos, 1999…

Gabor Kassay (13/9/2014)

7.  I am very sad to lean that Siegfried passed away. He was a very warm-hearted person and I had met him on several occasions and had carried out some discussions with him on Generalized convexity. My own younger brother did his PhD in Economics from UC Riverside and had taken a course in optimization from Siegfried and he still remembers him fondly.

Joydeep Dutta (13/9/2014)

8.  In this sad occasion, I would like to express my sincere condolences to Professor Siegfried Schaible’s family and members of the Working Group on Generalized Convexity. We all admit that one of his capabilities was to persuade novice researchers in the area of Generalized Convexity and generously provide them with new ideas.

I feel obliged to hereby pay tribute to him and his outstanding leadership of our group.

Jafar Zafarani  (13/9/2014)

9. Please accept my heartfelt sympathies for our loss. Our thoughts and hearts are always with you.

Mitra Salehi  (13/9/2014)

10. Dear Siegfried, we had the honor of working with you for many years and enjoy your precious guidance and friendship. Thank you for being so close to us and also to our families, sharing moments of study as well of relax. In every moments, you have never missed your sensitivity, availability and friendship. Thanks again Siegfried, you will always be with us.

Elisabetta Allevi and Adriana Gnudi  (13/9/2014)

11.  Siegfried was a flurry of activity and has spared no effort and willingness to inform us regularly and respond to numerous messages.

We are certainly many people to regret him.

Abd Raouf Chouikha (13/9/2014)

12. Professor Siegfried Schaible was an excellent colleague and a dear friend.  I have had the honor and privilege a of being his co author on two papers and one major book.  He was a world leader (perhaps THE world leader) in the field of generalized convexity and monotonicity.  His dedication and zest to his research attracted many others, including myself, to join his path.  He was very influential on my early stage research career and I cherished the dialogues and fierce discussions with him.

He was indeed a truly unique and remarkable person.

He will be missed and remembered.

Israel Zang (14/9/2014)

13. We are deeply sadden to read that Siegfried passed away. Siegfried was a very gentle personality, an excellent mathematician and a great organizer. He was the founder of our Working Group on Generalized Convexity and we attended many of his outstanding conferences. We admire him and will keep him thankful in our memories.

Diethard Pallaschke and Ryszard Urbanski (14.09.2014)

14. I miss a dear friend who introduced me to the community of generalized convexity and monotonicity

Joachim Gwinner (14/9/2014)

15. It has been very sad to know that Professor Siegfried Schaible has passed away. He has left behind a legacy which I am sure will be carried forward by a large community of researchers working in generalized convexity and monotonicity. I met Professor Siegfried Schaible on a few occasions during international conferences in Greece, Singapore and Vietnam and had the privilege of sharing many memorable moments together. May his Soul Rest in Peace.

Pankaj Gupta (14/9/2014)

16. His warm smile, hearty laugh and calm demeanor will always be missed. He was gentle and giant – made it into so many hearts. Rest in peace sir.

Aparna Mehra (14/9/2014)

17. I don’t know Prof. Schaible personally, but always thought of meeting him in some conference. I know him only through his papers in fractional programming. He was a great researcher and visionary. May his soul rest in peace. 

Vikas Sharma  (15/9/2014)

18. May God provide piece to the great soul.

We all are grateful to his guidance and warm behavior of Prof. Siegfried.

Shashi Kant Mishra (15/9/2014)

19. I am very sad to learn that Siegfried passed away.  Over the years we had together many opportunities to meet and to exchange and I appreciated Siegfried very much as a man and as a mathematician. The community of generalized convexity owes him enormously. Thank you Siegfried for all you did and for all your work. You will remain in our thoughts.

Michel Théra (15/9/2014)

20.  I am very sorry to read this sad news. I will keep Prof. Schaible’s kindness and helps on our past research collaboration in my mind. May his soul rest in peace.

Hui-Ju Chen (15/9/2014)

21. I am deeply saddened to learn about the sad demise of Prof Schaible.I recollect meeting him at Edmonton during the summer of 1985 when I was visiting Prof Bector at the University of Manitoba.I had the privilege of spending a couple of days with him. He was an excellent person, extra ordinary researcher and a great motivator for young researchers here in India. May His Soul Rest in Peace.

Suresh Chandra (15/9/2014)

22. Siegfried Schaible passed away… I got particularly sad learning the news this morning, at Santiago of Chile.

Apart from being a friend and a co-author, he was a very warm person. Last but not least, I am indebted to him for his valuable help at the beginning of my carrier.

Aris Daniilidis  (15/9/2014)

23. Even though I was already informed of the precarious health that Siegfried had in the last times, I have been very sadly impressed by the news that he passed away. I met Siegfried for the first time at the ISMP held in Bonn in 1982 and, after meeting him again at several other conferences, we became friends. We visited each other and coauthored one paper, joint with Alex Rubinov. I am proud to say that I attended the dinner, at an Italian restaurant in Ann Arbor during the 1994 ISMP, when he proposed the creation of the WGGC to Bruce Craven, Sándor Komlósi and me. Since then he has been the soul of our group, and I am sure that his memory will continue inspiring us. We will miss his warm personality and his characteristic optimism and good sense of humor.

Juan Enrique Martinez-Legaz (16/9/2014)

24. Since I did not know about Siegfried’s health problems I was highly shocked by the message. My joining our group is due to him: Only two months before GCM5 in Luminy I became aware of his work on generalized monotonicity which was related to my own research in economic theory. I wrote to him and he proposed to participate in the symposium. However, it was almost too late to register but, fortunately, Siegfried managed my participation. This conference was the beginning of a long period within which I have met many kind colleagues stimulating my own work. I owe this experience to Siegfried and, needless to say, I am deeply grateful to him.

Reinhard John (16/9/2014)

25. I am sorry to learn about the demise of Professor Siegfried Schaible. It is almost impossible to think about WGGC symposiums without his presence. However, his immense contributions and commitment to work would continue to motivate many of us.

With fond memories

C.S. Lalitha (16/9/2014)

26. Dear Siegfried, I will always remember the nice time we spent together: we started our scientific collaboration twenty years ago but you became soon a dear friend of me and of my family. In these days I am looking at the photos we took together in Stresa and in Milan  (surely less than yours…) and many pleasant memories  come back to my mind. Thank you for your friendiship and guidance.

Monica Bianchi (17/9/2014)

27. Let me send my deep condolences to Professor Siegfried Schaible’s Family and Collaborators.

I studied his papers on vector optimization and variational inequalities.

I met him several times in Taiwan and in other countries.

I always recall his kindness and warm attitude to other people.

Nguyen Dong Yen (17/9/2014)

28. I and my family ( my wife, daughter and son ) are very sorry to hear the sad news that Siegfried passed away. We would like to express our deepest condolences to his family. I met him several time in UC Riverside, Busan- Korea, European and Asian countries.

Especially, the one year 2002 in California bring back lots of good memories. In those days, I had a good time and job with him to write two nice cowork papers, to attend INFORMS Annual Meeting 2002-San Jose and so on. I respect to his academic activities and scientific research works and so I always look up to Siegfried.

Do Sang Kim (19/9/2014)

29. I  became  very sad when I heard that  Professor  Siegfried Schaible passed away.  We had two joint papers and I learned too much from him. He was one of the greatest mathematicians who I have ever seen.  In my opinion we lost a valuable person who could add some interesting results to mathematics and be as a leadership. I will keep him in my heart and I wish   his soul rest in peace.

Ali Farajzadeh (19/9/2014)

30. it¢s shocking to know the sad news that Siegfried Schaible passed away the morning of September 8.

He was a legend in the fields of generalized convexity, generalized monotonicity, variational inequalities, and many other fields in optimization. Unfortunately, I could not meet him personally, but his literature always helped me a lot.

He is physically no more, but the light of his work will keep on guiding us all through the darkness of ignorance.

He will always remain in our hearts.

Vivek Laha (19/9/2014)

31. I am sad to read that Siegfried passed away. He was a courageous person, especially during these last few years. His energy, activity and his sense of humour remain stimulating for us. He has done much for our community and we must remain grateful and thoughtful to him.

Jean-Paul Penot (19/9/2014)

32.  I first met Siegfried in Lausanne, at the 16th Symposium  on Mathematical Programming. Since then, I remember him very active and energetic all the time. He was ready to discuss various subjects in a very friendly manner and had  many friends from lot of countries. I also felt his benevolence during our joint work. His advices on publication of my book were very significant for me.

This is really big loss for our optimization community.

Igor Konnov (19/9/2014)

33. I am deeply shocked and very sad after this news.

May Almighty God forgive the deceased and rest his soul in heavenly peace in Jannah (near his wife)  and give patience and courage to the bereaved family to bear this irreparable loss (Ameen!).

Qamrul Hasan Ansari (20/9/2014)

34. It is so sad news that Professor Siegfried Schaible has gone. I appreciate that I have several times met his wonderful smile at the international mathematical conference. I have respect for his life as a great mathematician. I pray for the repose of him in peace.

Hiroko Manaka (20/9/2014)

35. I would like to express my sincere condolences to the family of Professor Siegfried Schaible and to all members of our Working Group on Generalized Convexity and Monotonicity. I met Siegfried during the  international conferences organized in Samos 1999 and in Varese  2005 and I had the honor of being his co-author on one paper. He was a very nice and helpful person and a great mathematician.

Ouayl Chadli (21/9/2014)

36. I am truly sorry to hear the sad news of my sincere friend Siegfried. God bless his soul, and grant all his love ones patience. Siegfried was a great friend, colleague, and first class scholar. I enjoyed his company, his great sense of humor, and his lovely family. He will be dearly missed by all of us at School of Business Administration at University of California, Riverside. I am sorry that I could not attend his funeral and express my condolences in person as I am currently working in Riyadh, Saudi Arabia. My sincere condolences to all members of his family, and friends.

Bajis Dodin  (22/9/2014)

37. The sad news of Sieg-Fried Schaible no longer with us came very sudden. My deepest condolence goes to the grieving families. His passing away is also a great loss to all of us as his friends and colleagues.

Well known for his accomplishment in generalized convexity & monotonicity, Seig-Fried is also known for his warmth and kindness. Professor Schaible and I were both chair professors at Chung Yuan Christian University, Taiwan. Thus I had the honor to work with him closely for more than 2 years. His work had inspired me of some revelation in my work of Minimax Programing problems. He told me his name Seig-Fried means Victor-Peace, therefore, together with Professor Tamaki Tanaka, we named him a Chinese name with the same meaning .謝勝平.. He loved this Chinese name and used it with us in Taiwan all the time.

Seig-Fried will be remembered as a distinguished math scientist and a good friend. His persistence in pursuing research work and his warm and kind fellowship are admirable. He had gone through a fulfilling life journey. May he rest in peace!

Hang-Chin Lai (20/9/2014)

38. I am deeply saddened by the news of Professor Siegfried Schaible passing.  My thoughts and prayers are with him. I know Professor Schaible by his excellent book (Generalized Concavity).  I met him in GCM10, in Romania, and I found him a real gentleman and a perfect scientist.  

Please accept my sincere condolences for our loss.

Mohammad Hossein  Alizadeh (23/9/2014)

39. My first meeting with Siegfried was in Clermont in 1979, I invited him together with Jacques Ferland who was in sabbatical in Montpellier. I have just obtained my thesis, Siegried was still in Koln and it was an opportunity for me to be in connection with the two people having contributed to quadratic quasiconvex functions. It was the beginning of a long a fruitful friendship.

Siegfried spent a lot of energy in the promotion of generalized convexity and he is at the origin of the working group.

I was sad in learning his death.

jean-pierre crouzeix (23/9/2014)

40. I am very sad to lean that Siegfried passed away. He was a Kindly person.  His passing away is also a great loss to all of us as his friends and colleagues.  May his soul rest in peace.

Shun-Chin Ho (23/9/2014)

41. I would like to express my deep condolences and warmest feelings to Siegfrieds children. I appreciated his scientific guidance and personal friendship to me since our PhD study long years back at the University of Cologne (Germany). I keep precious memories of the kind hospitality of Siegfried and his wife Ingrid. I will miss his warm-hearted personality and his encouraging believe in Jesus Christ.

Reinhard Haupt (23/09/2014)

42. It is with great sadness that I write this note on my good friend and mentor Professor Siegfried Schaible. May god bless his soul and grant his family serenity and patience. Professor Schaible was one of the greatest scholars I had the privilege and the honor to work with. He was a true scholar, thoughtful, wise and very respectful to his colleagues. Professor Schaible’s research made great impact in several fields starting with his early work on Fractional Programming and ending with his work on Generalized Convexity. Throughout his career, his work has generated over 6900 citations. Professor Schaible was one of the few, in the University of California, to be elected AAAS-Fellow of the American Association for the Advancement of Science, in 1998.

I will certainly miss my office neighbor, his sense of humor and sophisticated jokes. May God bless his soul and grant him his heavens.

Mohsen Elhafsi (23/9/2014)

43. May Allah forgive him and cleanse him of his transgressions as white cloth is cleansed of stains. May Allah take him into Paradise. May Allah give his family and friends strength and comfort Ameen…

Sahar Mohamed Ali Abou Bakr (25/9/2104)

44.  I am very sad to read that Professor Siegfried Schaible  passed away. I have several times met him in Taiwan. I can’t forget his wonderful smile.

I wish his soul rest in peace.

Tone-Yau Huang  (1/10/2014)

45.  It was with great sadness and shock that I came across the memorial webpage for Siegfied. I met Siegfried originally in 1980 when I started my career at The University of Alberta. Siegfried was a very active researcher and, as mentioned by many, one always remembers his happy demeanor and fantastic smile. Siegfried was one of the three organizer of the First NATO conference on Generalized Concavity in Vancouver, Aug. 1980. This was one of the first conferences that I attended and was fantastic. And it led to the classic book and I assume WGGC. My wife worked with Siegfried as well before changing to differential equations.

Please accept my ‘late’ sincere condolences to his family and to all his friends.

Henry Wolkowicz (17/8/2018)

46. It is shocking to hear of Professor Schaible’s passing. At this point it is 6 years after he has left us but for me this just as sad. I was one of his students at the MBA program at UC Riverside and he was instrumental in introducing me to and then inspiring me to study mathematical programming and heuristics in my future graduate studies. I was his TA and RA for a number of quarters and will always remember his jovial and friendly nature both in class and outside. In his first meeting with me he asked me how to pronounce my name and what it meant and never forgot it. An impressive person both as an academic and a human being I wish his family the best and hope his soul rests in peace as part of the eternity of the universe.

Rakesh Gupta (17/5/2020)