Rafi Blumenfeld ...

... and theoretical physics: a never-ending story



Our recent highlighted paper in Phys. Rev. Lett. is making a bit of news

Organising a conference (with Mike Cates and Mark Warner) Soft Matter - Theoretical and Industrial Challenges, Celebrating the Pioneering Work of Sir Sam Edwards, Cambridge, UK, September 7 - 9

Invited talk at the American Physical Society (APS) meeting, Baltimore, MD, USA, March 14 - 18: "Granular statistical mechanics - Building on the legacy of Sir Sam Edwards" (Abstract)

Invited talk at the conference Dynamic Days, Durham, NC, USA, January 7 - 10: "Granular statistical mechanics - Status report and future directions"


Talks at the workshop Soft and granular matter in ambient and extreme conditions 2015, NUDT, Changsha, Hunan, August 31 - September 4: 1. "Advances in Granular statistical mechanics - I"; 2. "Advances in Granular statistical mechanics - II"

Talk at the KITPC workshop on Controlled structure formation of soft matter, CAS, Beijing, August 17-21: "Granular statistical mechanics – Following the legacy of Sir Sam Edwards"

Talks at the 2015 Annual Meeting of Thermodynamic and Statistical Mechanics Education and Research Association of China, Hunan, July 12-15: 1. "Statistical mechanics of athermal systems"; 2. "Statistical mechanics of granular, porous and cellular smaterials"; 3. "Discussion: Necessary curriculum for physics undergraduates"

Talk in Jiao Tong University, Shanghai, July 7: "Towards a stress theory for real granular materials"

Organising an International Workshop on:
Soft and granular matter in ambient and extreme conditions 2015 (SGMAEC2015), Changsha, Hunan, China, 31/08-04/09 September

Talks at the EMI2015 conference, June 16: 1. "From local structural characterisation of porous materials to structure-property relations: a systematic approach"; 2. "Structural evolution of 2D granular solid under shear deformation"

Talk at the one day "Beijing Soft Matter workshop", April 17: "A local morphological descriptor of granular materials and its uses"

Appointed "1000-talent plan" expert in College of Science, NUDT, Changsha, China; it came with a nice research award

I have a 2-year Postdoctoral Research Associate position available at the Physics Dept. of NUDT, Changsha, Hunan


Invited talk on:
Local structural characterisation and statistical mechanics of porous and cellular media, at the Conference "Avalanches in Functional Materials and Geophysics", Cambridge, UK, 4-8 December,

Seminar on:
Fracture propagation in geo-materials - The single fracture dynamics, in the College of Civil Engineering, Tongji University, Shanghai, China, 24 September

Organising an International Workshop on:
Soft and granular matter in ambient and extreme conditions, Changsha, Hunan, China, 15-18 September

Seminar on:
Structural characterisation and statistical mechanics of granular and porous systems: A systematic method to derive structure-property relation and equations of state, in the Inst. of Theoretical Physics, Chinese Academy of Science, Beijing, China, 17 July

Seminar on:
Towards a fundamental stress theory for real granular materials, in Beihang University, Beijing, China, 16 July

Appointed a "Distinguished Professor" in NUDT, Changsha, China

Talk at the conference:
Foams and Minimal Surfaces - 12 Years On 24-28 February, Cambridge, UK

Talk at the conference:
Imperial College Consortium on Pore-Scale Modelling 13 January, London

Talk at the conference:
Dynamic Systems: From Statistical Mechanics to Engineering Applications 9-10 January, Zurich, Switzerland

Paper published in Phys. Rev. Lett.:
On universal structural characteristics of granular packs, T. Matsushima and R. Blumenfeld, Phys. Rev. Lett. 112, 098003 (2014)

Invited to deliver a six-hours lecture series and a research seminar in the
International Winter School and Symposium on Statistical Mechanics and Simulation of Nonlinear Dynamics
3-7 January 2014, Changsha, China

Rafi 10/2009

These pages have grown uncontrollably from a modest beginning in 1993, when a home page was a rarity. I cannot pinpoint when exactly over the years was it that I lost the fight against this unstable self-(dis)organised growth. I was probably never in control. My publication list is updated regularly, after a fashion. The rest not so much. If your time is short, I recommend to start with the 'research interests' page and possibly continue to the 'Selected publications'. You are, of course, welcome to visit all the pages but be warned that there is always the possibility of getting lost in the overgrown meandering paths.

Often, when I finish developing a model or a theory, I write a limerick that summarises it. Below are the limericks I have written so far, each with a link to a paper that the work produced, if it has.

On Force Chains paper
Rafi 10/2009
Force chains can be found
And in granular materials they abound
Now although isostaticity
Has caused great turbidity
That particular stress theory is sound

(RB April 2006)

On Stato-elasticity I (paper in preparation)
Rafi 10/2009
Some put their faith in Elasticity
Others swear on Isostaticity
But I stand before you
To tell you boldly
That Stato-elasticity is the one and only

(RB April 2008)

On Stato-elasticity II (paper in preparation)
Rafi 10/2009
A theory called Elasticity
Was challenged by Isostaticity
But I tell you boldly
That real packs mostly
Should follow Stato-elasticity

(RB April 2008)

On Couette flow of da Vinci fluids paper 1, paper 2
Rafi 10/2009
O' whirling sands in the cylinder flow
Layer by streamline they clump and they slow
Grains rub their neighbour
Dissipating much labour
And da Vinci fluids explain it, gung-ho!

(RB November 2010)

Polymer chain pullout with AFM paper 1, paper 2
Rafi 10/2009
Pick a polymer chain with the tip
Bond it tight, don't let it slip
It pulls out in a stutter
Here a jump, there a flutter
Thus, through the tube it would not zip

(RB April 2006)

Fractures propagating in disordered materials paper 1, paper 2
Fractures evolving in disordered matter
Spawn voids that expand, grow large and scatter
Swallowed by the crack
With a supersonic smack
They get to become part of the big antimatter

(RB September 2014)

On modeling Disordered Auxetics paper 1, paper 2
Rafi 10/2009
On pulling they swell, on pushing they dense
Auxetic materials defy common sense
They expand and dilate
Causing heated debate
But iso-auxeticity dispels the suspense

(RB June 2015)

On contact granular statistical mechanics I (paper in preparation)
One moment they're there and then they are gone
Inter-grain contacts do not linger on
Their dynamics mysterious
And their modelling spurious
But contact potential explains it, c'est bon!

(RB December 2015)

On contact granular statistical mechanics II (paper in preparation)
Shear them to slide and knock them to clap
Inter-grain contacts are an energy trap
Their dynamics obscure
To the theorist's pure
But contacture statistics fills out the gap

(RB December 2015)

On Sam Edwards
Rafi 10/2009
He pushed science to places unmanned
Made physics of squishies and sand
Fokker-Planck here
Replica there
And all with some wit and Chablis glass in hand

(RB April 2016)

On Force Chains Curving Back (paper in preparation)
Rafi 10/2009 Rafi 10/2009
Back-curving stress chains in cylinders loop
Detected and measured in Behringer’s group
They leak to the cone
They branch on and on
And isostaticty explains all this soup

(Experimental figure courtesy of Jie Zhang)
(RB April 2016)