Bhavesh Valecha

In Dresden for SOEAM25 at @mpipks.bsky.social? Find me and my poster on this work #oneposterafteranother

Meet the 2025 Ig Nobel Prize winners The annual award ceremony features miniature operas, scientific demos, and the 24/7 lectures.

Heartiest congratulations to @gbart.bsky.social and team for winning the physics Ig Nobel prize. An achievement to live up to as a fellow physicist 🫡
arstechnica.com/science/2025...

Scientists eager to build a community interested in the control of complex nonequilibrium phenomena, come together this week at the Lorentz Center to establish some fruitful connections between recent theoretical and experimental progress. bit.ly/4ge4Fu2

If you find this interesting, find me and my poster at @lorentzcenter.bsky.social during the workshop Nonequilibrium Systems under Control from 8-12 Sept, and at the Self-Organizing and Evolving Active Matter workshop at @mpipks.bsky.social from 22-26 Sept :')

This brings me to the end of a number of firsts - first #bluesky post, first thread, first PhD publications. Thanks for reading :') 12/12

Transport of partially active polymers in chemical gradients The transport of molecules for chemical reactions is critically important in various cellular biological processes. Despite thermal diffusion being prevalent in many biochemical processes, it is unrel...

Check out more details here:
pubs.rsc.org/en/content/a...
Big thanks to Shashank Ravichandir and colleagues at IPF Dresden for this collaboration :) 11/n

Symbols represent Brownian dynamics simulation data, whereas solid lines represent theoretical prediction.

Furthermore, we find that the dynamics of these chains is also affected by the number and location of active units. We report this using the mean first passage time required to reach location of highest activity, which decreases with increasing number of active units. 10/n

Red sphere represents active units and blue ones represent passive units. Symbols represent Brownian dynamics simulation data, whereas solid lines represent theoretical prediction.

We report that different locations and number of active units in the chain lead to different accumulation behaviour. Surprisingly, chains with fewer active units do better than chains uniquely composed of ABPs. 9/n

We again consider this system in activity gradients and want to determine if the accumulation behavior can be controlled by the location and number of active units in the chain. Further, we also check how the dynamics are affected by the same metric,i.e. are chains with more active units faster? 8/n

Next, to study systems akin to chromosomal loci, we consider active Rouse chains, composed of both ABPs and passive ones. The presence of ABPs in only parts of the chain is inspired by the presence of active components like kinesin motors stressing certain parts of an otherwise passive network. 7/n

Active transport of cargo-carrying and interconnected chiral particles Directed motion up a concentration gradient is crucial for the survival and maintenance of numerous biological systems, such as sperms moving towards an egg during fertilization or ciliates moving tow...

Check out the nitty-gritties of this study here
pubs.rsc.org/en/content/a...
Thankful to Dr. Hossein Vahid at IPF Dresden for this fruitful collaboration :) 6/n

q represents the size of the passive Brownian particle with respect to the cABP. Symbols represent Brownian dynamics simulation data, whereas solid lines represent theoretical prediction.

Moreover, with a large enough chiral torque composites with small passive counterpart can also accumulate in high activity. This goes further than previous studies (PRL 126, 208102) where accumulation in high activity was possible only beyond a certain size of the passive part of the composite. 5/n

\Omega is the chiral torque, \rho is the density of the cABP connected to passive Brownian particle, and fs is the activity field. Symbols represent Brownian dynamics simulation data, whereas solid lines represent theoretical prediction.

Starting with stochastic differential equations followed by coarse graining, we find that the accumulation behaviour can be tuned using the chiral torque. This gives another handle on controlling the accumulation of ABPs, complementing new experimental setups with magnetotactic swimmers. 4/n

First, to capture the rotational aspect of sperm motion, we consider the simple case of a chiral active Brownian particle (cABP) connected to a passive one. This system is in an activity gradient to simulate chemical gradients, and we want to know where this system migrates to and accumulates. 3/n

Not only in cartoons, but this directed motion is prevalent in many biological systems, for eg, sperms migrating towards egg during fertilisation, and chromosomal loci dynamics during interphase. Motivated by these examples, we try to model them using standard active matter models in two studies 2/n

mickey mouse is doing a handstand on the ground while wearing a hat and gloves . ALT: mickey mouse is doing a handstand on the ground while wearing a hat and gloves .

A very very #latepost, but super happy to kick-off my #bluesky profile by announcing the first couple of results from my PhD. Now, we have all grown up seeing our favourite cartoon float towards food, but can we mimic this behaviour in #activematter systems, which lack such a sense of smell? 1/