Any space that is contained with boundaries where the particles contained inside those boundaries cannot tell the particles on the other side of those boundaries exist is by definition a universe as stated in definition 2 in the following.
Definition of universe
1 : the whole body of things and phenomena observed or postulated : cosmos: such as
a : a systematic whole held to arise by and persist through the direct intervention of divine power
b : the world of human experience
c (1) : the entire celestial cosmos (2) : milky way galaxy (3) : an aggregate of stars comparable to the Milky Way galaxy
2 : a distinct field or province of thought or reality that forms a closed system or self-inclusive and independent organization
3 : population 4
4 : a set that contains all elements relevant to a particular discussion or problem
5 : a great number or quantity
a large enough universe of stocks … to choose from —G. B. Clairmont
By that definition an atom could be a universe since we can only detect the boundary of the atom (electron cloud) and cannot observe the interior of the atom because inside that boundary is a separate universe. Some postulate that space can be broken down into smaller universes that are two particle (antiparticle-particle strings that are one dimensional universes) called string theory. The higgs mechanism is how the universe inside the atom interacts with the universe outside the atom if all of space is made up of these multiple unverses constructed of strings.
I would suggest that a higgs boson is made up of two of these strings and is a four particle universe containing two intertwined two particle universes. But, that would require a lot of order and, the initiation of such universal order is hard to explain by purely natural causes (even though it solves a lot of problems by creating while creating that initiation problem).