Yes, superstructures and cosmic filaments can indeed act as gravitational lenses. Gravitational lensing is a process wherein a large mass, such as a galaxy or galaxy cluster, bends the light from objects behind it, such as more distant galaxies or quasars. This bending causes the background objects to appear distorted, magnified, or even multiplied from the perspective of an observer.
Superstructures, which include large formations of matter such as galaxy clusters and even larger assemblies like superclusters, possess significant gravitational fields capable of affecting light in this manner. Similarly, cosmic filaments, which are vast thread-like formations of galaxies and dark matter that weave through the universe, have enough mass and gravitational pull to lens light.
These gravitational lensing effects not only provide important evidence for the presence of dark matter—since it doesn’t emit light but has gravitational effects—but also serve as a powerful tool for observing distant parts of the universe. By studying how light is bent by these massive structures, astronomers can infer the distribution of mass in the universe, gain insights into the large-scale structure of the cosmos, and examine the properties of dark matter.