Why are players wearing black armbands during the India vs England Lord's ODI?

Players from India and England wore achromatic armbands to grant Sir Gary Sobers. This tribute occurred earlier the 3rd and last ODI lucifer astatine Lord's. England skipper Harry Brook won the flip and elected to bat first. India made respective changes to their squad owed to subordinate injuries. The lucifer was important with the ODI World Cup approaching.