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A WORLD IN A GRAIN OF SAND. “The two scalar modes Ψ and Φ, relevant for cosmological observations in the physical universe, play an important role in the gravity analogue for granular matter. We fo- cus on the effect of external stress perturbations on the changes in the analogue spatial geometry.” https://lnkd.in/dusKMKM View in LinkedIn

SHEAR STRESS. “Clearly, the shear stress has been applied on an already spontaneously jammed isotropic state, to show that anisotropic structure formation results because of this external stress perturbation. This implies that, in the gravity analogue as per the Rachaudhuri equation, θ(0) < 0, so that we have a convergent geodesic congruence.” https://lnkd.in/dusKMKM View in LinkedIn

GRANULAR SAND. “Granular media are known to exhibit a richer variety of density fluctuations under externally applied stress, especially a shear stress.” https://lnkd.in/dusKMKM View in LinkedIn

RESPONSE TO PAPER. “As for reactions, it's really a mixed bag. We've had very positive reactions from a small number of young aficionados of granular matter, who've thought our proposed analogy as `very, very interesting'. On the other hand, senior experts appear to be much less enthusiastic and even skeptical. This isn't surprising, given that in today's world people are concerned about their own niches, and losing even an inch of their domain to a group of novices isn't welcome. The paper isn't published yet, but the fight with reviewers is on, so lets see. With our best wishes, Partha (Majumdar).” View in LinkedIn

BLACK HOLE FORMATION. “A more realistic situation for appearance of trapped surfaces is gravitational collapse. Here, the stress-energy tensor vanishes outside the boundary of the collapsing body (assumed spherical for simplicity).” https://lnkd.in/dusKMKM View in LinkedIn

SAND LINKS TO THE COSMOS. “Similarly, aspects of the CMB spectrum like non-Gaussianity may also show up as a feature of granular media observed experimentally. All-in-all, the assay portends an interesting future.” https://lnkd.in/dusKMKM View in LinkedIn

FRAME BY FRAME. “The spatial symmetries of granular interactions are manifest in every frame of the gravity analogue.” https://lnkd.in/dusKMKM View in LinkedIn

FEARLESS THINKING. “Perhaps one can also turn the analogy on its head, and use granular matter physics to explore phenomena that are yet unobserved in real cosmology. An example would be the existence of primordial gravitational waves which in the real universe are still shrouded in mystery.” https://lnkd.in/dusKMKM View in LinkedIn

THE BLACK HOLE. “The length scale rS characterizing this solution is called the Schwarzschild radius; r = rS is identified with the event horizon, and represents the boundary between events connected to asymptopia and those that are confined to the region r ≤ rS - the black hole region.” https://lnkd.in/dusKMKM View in LinkedIn

MAKING THE DATA FIT THE MODEL. “The analogue of Hubble friction in that case may help stabilize and stimulate growth of structures in the density profile. This is certainly a direction worthy of exploration.” https://lnkd.in/dusKMKM View in LinkedIn