Gamma-Jacobson Radicals in n-ary Γ-Semirings
- Gamma-Jacobson radicals are a generalized form of the Jacobson radical for n-ary Γ-semirings, incorporating noncommutative and higher-arity structures.
- They leverage modular maximal ideals and positional conditions to introduce novel definitions of n-ary primeness and semiprimality.
- This framework enables spectral topology analyses and Wedderburn–Artin-type decompositions, advancing representation theory in complex semiring structures.
Gamma-Jacobson radicals generalize the classical Jacobson radical to the setting of noncommutative and -ary -semirings. The development of Gamma-Jacobson radicals is motivated by the need for a unified radical theory accommodating both higher arity and noncommutative phenomena, including positional (left/right/two-sided) structure and modular maximality constraints. These radicals allow for the characterization of semisimplicity, primitivity, and the intersection-theoretic core of -semirings, both in the classical and higher-arity noncommutative cases (Gokavarapu et al., 18 Nov 2025).
1. -ary -Semirings and Modularity Foundations
An -ary -semiring is defined as a quadruple
where is a commutative additive semigroup with identity $0$, 0 is an additive semigroup, and the 1-ary product
2
satisfies additivity and zero-absorption in each slot, along with full 3-ary associativity under the action of 4. In this setting, modular maximal ideals are those two-sided ideals admitting a quasi-unit relative to the 5-ary product structure—these play a pivotal role in the construction of the Gamma-Jacobson radical.
2. Ideals and (n, m)-type Structures
The foundational extensions of ideal theory to higher arity and noncommutativity lead to the concepts of left, right, and two-sided ideals. For 6, left ideals satisfy closure under products with the second input in the ideal, while right and two-sided ideals use analogously indexed conditions. In the general 7-ary case, an 8-ideal is a subsemigroup 9 such that for any nonempty 0, the 1-ary product is closed in 2 when all inputs indexed by 3 are in 4.
A further refinement establishes 5-type ideals: for 6, 7 is an 8-ideal if for any 9, the number of entries from 0 at least 1 implies closure under 2. The minimal such 3 is the arity-threshold 4. A decomposition theorem clarifies that every 5-ideal can be viewed as the intersection of all 6-ideals with 7.
3. 8-ary Primality, Semiprimality, and Radical Closures
Primeness and semiprimality are 9-ary generalizations, defined as follows:
- 0-ary primality: A proper 1-ideal 2 is 3-ary prime if 4 implies that some 5.
- 6-ary semiprimality: A two-sided ideal 7 is 8-ary semiprime if for all 9 and 0, 1 (where 2) implies 3.
The 4-ary prime radical of 5 is
6
with an alternative, diagonal characterization: 7 This operator is a closure, and 8 is 9-ary semiprime if and only if 0.
4. The Gamma-Jacobson Radical: Construction and Properties
For any 1-ary 2-semiring 3, the Gamma-Jacobson radical is defined as
4
where 5 is the family of all modular maximal two-sided ideals—that is, those admitting a quasi-unit.
Fundamental properties:
- 6 is always 7-ary semiprime.
- 8 if and only if 9 is 0-ary 1-semisimple.
- If every modular maximal ideal is 2-ary prime, then 3 coincides with the intersection of all maximal ideals.
A plausible implication is that this framework presents an extension of semisimplicity, primitivity, and radical theory simultaneously for commutative, noncommutative, and higher-arity semirings.
5. Zariski-Type Spectral Topologies and Triadic Spectral Geometry
The radical theory is unified via spectral topologies: for each positional direction 4 (left, right, two-sided), 5 is the set of 6-prime ideals. Closed sets are defined by
7
with compact 8-topology, and the radical of 9 is recovered as the intersection of primes containing 0: 1 A triadic spectral diagram emerges in the fully noncommutative setting: 2 showing the two-sided spectrum as intermediary between left and right prime spectra.
6. Wedderburn–Artin-Type Decomposition and Representation Theory
Analogous to the classical Wedderburn–Artin theorem, if 3 is finite or semiprimary and 4, then minimal primitive (thus prime) ideals 5 exist with
6
Each 7 is a primitive 8-semiring acting faithfully on a simple module 9, and the decomposition is unique up to permutation. Minimal primitive ideals are pairwise comaximal, reflecting robust representation-theoretic simplicity and allowing a tight connection between the radical and module-theoretic simplicity in noncommutative/high-arity settings.
7. Illustrative Examples and Invariants
Several example constructions clarify the landscape:
| Example | Main Data (paraphrased) | Radical Consequences |
|---|---|---|
| Matrix semiring | $0$0, $0$1, $0$2 entrywise | Row-zero = left ideal; col-zero = right; their intersection = two-sided |
| Three-element system | $0$3, $0$4, $0$5, ternary product as in data | Distinct left/right prime radicals, $0$6 |
| Pinning construction | Given central idempotent $0$7, "pin" $0$8 slots to $0$9 to reduce arity | Ideals/radicals compatible under arity-reduction |
| Threshold invariant | For 00-ary 01, arity-threshold 02 measures coordinate closure | 03 |
The examples highlight the distinctions between positional and threshold properties and demonstrate the invariance and compatibility of radical theory under arity changes and noncommutativity.
Gamma-Jacobson radicals thus unify and generalize central decomposition and primitivity results, embedding classical, noncommutative, and higher-arity radical structures within a consolidated spectral and module-theoretic framework (Gokavarapu et al., 18 Nov 2025).