On of the solutions to scale Blockchain is using off-chain channels. You can find its definition here: (https://en.bitcoin.it/wiki/Off-Chain_Transactions).

However, one of the problem of off-chain channels is finding a suitable decentralized routing mechanism.

Since in Bitcoin, there is no routing table and transactions are only broadcast and also in general, we need to avoid centralized approaches for routing, is it practical to use Swarm Intelligence algorithms such as ACO (Ant colony optimization) for off-chain channels ?

Update: I refer you to a proposed Ant routing algorithm in the following paper as an instance of employing Swarm Intelligence for routing in Lightning Network. However, the paper has not been evaluated to demonstrate its performance.

You can find the proposed idea here: https://arxiv.org/pdf/1807.00151.pdf

One of the solutions to scale blockchain is to use off-chain channels. You can find its definition here: https://en.bitcoin.it/wiki/Off-Chain_Transactions.

However, one of the problems of off-chain channels is finding a suitable decentralized routing mechanism.

Since in Bitcoin there is no routing table and transactions are only broadcast and also, in general, we need to avoid centralized approaches for routing, is it practical to use swarm intelligence algorithms, such as ant colony optimization ones, for off-chain channels?

I refer you to a proposed ant routing algorithm in the paper Ant routing algorithm for the Lightning Network for an instance of employing ACO algorithms for routing in _lightning network. However, the paper has not been evaluated to demonstrate its performance.