My research interests
The following list is not only incomplete, but is also in constant evolution, which is
the hallmark of a true theoretical physicist, in my opinion. To keep studying variations
of the same problems means narrowing down and leads to one's fossilization, which I fight my hardest
to avoid. While this belief of mine had evident implications on my career (no one regards me as a
specialist on any specific problem) it has the advantage that it gives me a broad horizon and
leads quite a few physicists, who hold me in sufficiently high regard, to collaborate with me on
fundamental and practical issues, which keeps my disillusion with current science at bay.
On some of the projects below I have good collaborators and on others I don't.
Consequently, many of these issues are not progressing at a satisfactory pace.
If you would like to join effort, or you think that you have a problem that is related to
any of these issues, you are very welcome to contact me.
You can do so, even if the relation is remote because I can usually find connections between
seemingly unrelated problems and even if not I am always game for interesting ideas.
Current interests
- Pullout of single polymer chains, polymer dynamics near the glass temperature and implications:
A great deal of recent experimental effort is devoted to pulling single polymer and biological molecules and measuring the forces involved. These experiments reveal a very rich behaviour. I have constructed a model to understand the dynamics of such processes in the vicinity of the glass transition temperature. I currently explore the implications of my model on viscosity measurements in this regime, with the rather ambitious goal of trying to bridge between the melt- and glass-based models for polymer dynamics. My results also have direct implication to resistance of polymeric materials to failure at their interface as well as to plastic deformations of polymer glasses.- Stress transmission and yield flow in granular media and colloidal suspensions:
This work is relevant to powders, grain transport, mechanical and flow properties of sand, colloidal suspensions and more. We have formulated a first principles theory for the mesoscopic equations of stress transmission. For some systems, these equations are straightforward to upscale to the macroscopic regime (the holy grail in many fields of science and engineering), but in other systems this ios difficult due to effects similar to frustration in glassy systems. The work is carried out both theoretically and experimentally (My first ever experiment!).
- Moving curves in 3d and nonlinear dynamics of domain-wall solutions:
This fundamental study is relevant to a wide range of problems: geometric phases, spin chains (eg, the one dangling from your cursor is an example of a ferromagnetic Ising spin chain with one domain wall marked by the ball), protein dynamics, and domain formation in thin magnetic layers? I have some very intriguing results but hardly any time to build up a detailed file here. If you are very interested I will send you a list of my recent papers on the subject. - Stress transmission and yield flow in granular media and colloidal suspensions:
Past (but lingering) interests
- Mesoscale modelling and coarse-graining for use in numerical methods.
- Slow and fast cracking, and the rough surfaces that these result in.
- Characterization of hierarchical and fractal patterns beyond simple scaling.
- Theory for evolving unstable interfaces in Laplacian fields.
- Properties of strongly nonlinear and inhomogeneous/textured media - This is an old flame which is silently burning and waiting for an opportunity to erupt again.
- Electromagnetic waves in strongly nonlinear media.