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Congratulations to Subhash Khot for Nevanlinna Prize

August 12, 2014

I am delighted by the news that Subhash Khot was awarded the Rolf Nevanlinna Prize. I am reminded of a time (many years ago) when Robert Krauthgamer and I were arguing about one of Subhash’s papers if it is more of a Complexity Theory paper or more of an Algorithms paper. While this was a foolish argument then (and even more so now), it reflected our joint excitement by that work.

This is also a good opportunity to recall Boaz’ post on the unique game and other conjectures.

ICM survey: Computing on the edge of chaos

August 10, 2014
Guest post by Craig Gentry
The 2014 International Congress of Mathematicians (ICM 2014) is coming up in a few days, and (like Boaz said) we have a great collection of speakers in the “Mathematical Aspects of Computer Science” section. As it is the weekend, and I am sure that you are looking for excuses to avoid sunlight and socializing, let me point you to my survey on homomorphic encryption and obfuscation, intriguingly entitled “Computing on the Edge of Chaos: Structure and Randomness in Encrypted Computation“. Also, let this post also serve as a gentle and timely reminder to the other ICM speakers to hype their surveys.
As you read it, I think you will be surprised and delighted by the clarity of the concepts. Sadly (for me), this will not be due to the quality of my exposition (which is notoriously poor). Rather, despite everything you have heard, homomorphic encryption schemes have become embarrassingly simple. A couple of years ago, Boaz and Zvika remarked on this blog that homomorphic encryption schemes “have been simplified enough so that their description can fit, well, in a blog post…”. Since then, they have become even simpler. (As for obfuscation schemes, well, that’s a different story, and my survey keeps to the high-level concepts.) Enjoy!

FOCS 2014: Call for Workshops and Tutorials

July 26, 2014

As Boaz discussed, there is an excellent collection of papers to be presented at the upcoming FOCS in Philadelphia. These would be spread over three of the days of the conference.

Before this though, there will be an exciting day of workshops and tutorials. It is your chance to reach hundreds of people from across the community, and tell them about the latest developments in your exciting area. Organizing a workshop at FOCS takes away a bulk of the administrative work involved, and lets you concentrate on the more enjoyable scientific part. Below is the call for proposals for workhsops an tutorials. Send in your proposals.
http://www.cis.upenn.edu/~sanjeev/focs2014_workshops_call.html

Emanuele Viola presents: “behind the paper”

July 24, 2014

Emanuele Viola started a new series of posts which is related to the research life-stories project. In his words:

“the series “behind the paper” collects snapshots of the generation of papers. For example, did you spend months proving an exciting bound, only to discover it was already known? Or what was the key insight which made everything fit together?
Records of this baffling process are typically expunged from research publications. This is a place for them. The posts will have a technical component.”

Goin’ up, down, all around, it’s like a see saw*

July 16, 2014

This is my last research life-story (at least for now), possibly concluding this project (though you are all very welcomed to share more as long as this blog lives). My main hope was to give legitimacy to all of us to acknowledge and discuss our uncomfortable feelings and the “non-scientific” challenges of our careers. My experience with myself and others is that many of these neuroses are quite universal. And they are not necessarily correlated with success, which sometimes only adds internal pressure. Paraphrasing what Russell Impagliazzo told me the first time we met (years ago): we really are competing with ourselves, and this is a hopeless competition (I’m sure he said it better). As for myself, I feel that I learned how to enjoy our profession much more over the years (mainly through becoming a little less childish with time). Still, at times, I do feel inapt. Such a period is the topic of my last story.

During my last postdoc year, we had our first child. This was a wonderful event that I had been craving for years. But it was also very demanding. My son was colicky and we were inexperienced and mostly alone in the U.S. In addition we had three house moves, one of which was back to Israel (a move that was surprisingly non-smooth). I was very content with putting my young family at the center and I realized that this is a period that will not repeat itself and should be cherished (turns out that with kids, many periods are like that). I also understood that I cannot expect to do too much research at this period. There was nothing concrete I was worried about: I had just landed my dream position at Weizmann, I wasn’t worried about getting tenure, and I already had many results that I was very proud of (including one with Irit Dinur on PCPs that was quite recent). I could allow myself to take it easy, but my ego was not ready for that. With time, internal pressure accumulated. “Is this it? Did my creativity dry up? Is it downhill from now on?”

At the end of that year at Weizmann (with my son being just a bit over a year), I headed with my family to a summer trip to Berkeley (to work with Luca Trevisan and Irit Dinur) and to Cambridge (to Work with Salil Vadhan). I decided to invest all of the effort in problems related to RL vs. L and felt that this is a test for me. If I’ll fail, then I will scale down my expectation of myself. With this shaky (and so very silly) state of mind, I came to a complexity-theory workshop that started the trip. Though my talk about the work with Irit was very well received, I felt quite depressed. It felt like everyone have been doing these wonderful research and only I was idle. I especially remember one of these talks, with a speaker (who I knew to be very nice) that had an over-confident demeanor. Such individuals always put me off, but at this strangely vulnerable state of mind, it was a challenge to keep the tears inside.

The summer continued quite differently. Spending time with wonderful friends (who happen to be brilliant researchers), having a lot of time for vacationing with my family (thanks to Luca’s great life balance), and ending up with a result that exceeded all of my hopes (undirected connectivity in log-space). I remember very vividly the exact moment when two ideas that I had for many years suddenly clicked in an exciting new way. I remember pacing back and forth in our hotel room, going over the proof that then only existed in my mind. Could it be true? Surely not! But where could the bug be hiding? I remember going out to find a store that would have a notepad and pen for me to start writing the proof down and the slowly growing confidence that came from writing it down and every session of verification (Luca, Irit, Salil, …). And most of all, I remember all of the colleagues being happy with me and for me.

I am not sure if there is a lesson to be learned here. Perhaps, don’t believe everything you are feeling. Or at least – if you are neurotic, you are not the only one here.

* title inspired by Aretha .

FOCS 2014 Accepted papers list is online

July 15, 2014

The accepted papers list for FOCS 2014 is now posted online.

I am always amazed by the depth and breadth of works in the TCS community, and this FOCS is no exception. Whether you are a physicist interested in the possibility of general “area law” governing entanglement between different parts of systems, a geometer interested in Gromov’s topological notion of expanders, an optimization expert interested in the latest and greatest in interior point methods, a game theorist interested in Karlin’s longstanding conjecture on convergence of fictitious play, a complexity theorist interested in the latest efforts to separate the determinant from the permanent, or simply a dog owner or triangle lover, you will find something of interest in the conference. And of course FOCS is not just a collection of unrelated papers. A quantum computing expert would want to check the paper on topological expanders, as similar concepts have arose in the context of topological approaches to quantum error correction. An optimization expert might want to understand the convergence of “fictitious play” which is a very natural algorithm for solving linear programs, and of course since STOC 2014 we all know  that circuit lower bounds are tightly connected to improving the exponents of algorithms for combinatorial problems. This is just a taste and I could have chosen many other such examples, all strengthening Avi Wigderson’s point why we should all go to talks in areas other than our own.

I was also amazed by the effort reviewers and program committee members have put in the selection process. Conference reviewing sometimes get a bad reputation as being superficial. I did not find this to be the case at all. People have invested an amazing amount of work reading the papers, checking proofs, chasing down references, verifying technical points with the authors and other experts, and generally doing the best job they can to have an informed selection process and assemble the best program we can for the TCS community. I am sure we made mistakes, and the final program, as a product of a committee, is not fully consistent with any particular PC member’s taste, including my own. In particular, there were many submissions that some of us personally found novel and interesting, but were not included in the final program. But I do feel good about the process and believe that while some of our decisions may have been wrong, they were not wrong because we were superficial or lazy or cut corners due to the time pressure. Many times during this process I asked the PC members to go above and beyond what is typically expected, and they have more than risen to this challenge, often making heroic efforts to understand very complex (and sometimes not so greatly written) papers, and trying to get to the bottom of any misunderstanding. I am deeply grateful to them all.

Finally, some statistics. We accepted 70 papers, which is about 26% of the 268-273 submissions (depending on whether you count withdrawn ones). Aside from 9 submissions that were judged to be out of scope and received minimal reviewing, on average each submission had 3.3 reviews and 11.7 comments (including both comments by the PC and short comments/opinions by outside experts that were solicited in addition to the reviews.) Of course these numbers varied greatly based on how much attention and investigation we felt each submission needed and there was also extensive discussion on some of the papers during our two long days of the physical PC meeting. Finally, a very personal statistic for me  is that there are about 2800 emails in my “FOCS14″ folder.  As many past chairs told me, the best thing about this job is that you only do it once…

 

 

 

Collaboration, competition, and competition within collaboration

July 1, 2014

Another instalment on my research-life stories.

—————

The Talmud says: “competition/envy among scholars increases wisdom” (kinat sofrim tarbe chochma). Good or bad, competition is here to stay. Nevertheless, one of the strengths of our community is in its collaborative nature. This is good for science, but in my eyes also makes our life so much better. A recent example is a research project with Guy Rothblum. For a few weeks, we met quite regularly and every meeting went more or less as follows: First, we would go over the solution from the previous meeting and find a bug. Then we would work together on a new and improved solution. This sounds frustrating (and would probably have been frustrating if I worked alone), but instead it was a great joy. We got to solve this problem again and again, and in the process enjoy each other’s creativity and company. Unfortunately, our current solution seems quite robust, so our fun ritual ended.

My best example for turning competition into collaboration is in my long-term collaboration with Salil Vadhan. It started when Ran Raz and I had a modest result on Randomness Extractors (following the breakthrough work of Luca Trevisan). We then learned that Salil had the same result, and already managed to write it down. Salil invited us to join (and I’m sure he was a bit sad to lose his first single-authored paper), on the other hand, Ran and I decided to decline and give up on the result altogether (and I was sad to lose a paper at this early stage of my career). In retrospect, losing that result would have been quite inconsequential, and similarly for Salil. But what did turn out to be extremely significant was what happened next. The three of us started collaborating together, leading to a stronger paper and then an additional collaboration, and before long Salil and I established not only a long-term research collaboration but also a great friendship. The unfortunate accident turned out to be most fortunate after all! Not all collaborations end up so fruitful, but I almost never regretted a collaboration (DBLP gives me 74 coauthors so this is a large sample). I hope that the set of collaborators that regret working with me is equally small.

So let’s all choose collaboration over competition and happily ride into the sunset. Right? Well, not so fast. Collaboration and competition are not mutually exclusive. Turns out, we cannot shut down our egos even when we enter a collaboration. While I strongly believe that the contributions to a collaboration cannot be attributed to any one of the contributors, we all like to feel that we contributed our fair share and that we demonstrated our worth (to others and more importantly to ourselves). An over-competitive collaboration can be destructive, but in moderation it could indeed be that competition among scholars does increase wisdom.

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