Translation guide
The English word "invariant" refers to something that does not change. In Japanese, the most common equivalent is 不変 (fuhen), but depending on context, other terms like 普遍 (fuhen) or 不変量 (fuhenryō) may be used. This guide helps you choose the right expression.
Describing something that never changes, such as a principle, rule, or characteristic.
The most direct translation for 'invariant' in the sense of unchanging or constant. Used in both everyday and technical contexts.
自然の法則は不変だ。
The laws of nature are invariant.
彼の信念は不変だった。
His beliefs remained invariant.
A more colloquial way to say 'unchanging' or 'constant'. It is the negative form of 変わる (to change).
彼女の笑顔はいつも変わらない。
Her smile is always invariant.
A formal or literary term meaning 'constant' or 'invariable'. Often used in scientific or philosophical contexts.
宇宙の恒常性について議論する。
We discuss the invariance of the universe.
Describing something that is true or valid in all cases, without exception.
Means 'universal' or 'omnipresent'. It is often used for truths or principles that hold everywhere. Note: same reading as 不変 but different kanji and nuance.
この原理は普遍的に成り立つ。
This principle holds invariant universally.
The adjectival form of 普遍, meaning 'universal'. Commonly used in phrases like 普遍的な真理 (universal truth).
A quantity or property that remains unchanged under a transformation or set of operations.
The standard term in mathematics and physics for an invariant quantity. Literally 'unchanging amount'.
この系ではエネルギーが不変量である。
In this system, energy is an invariant.
Specifically refers to an invariant expression or formula in algebra. Less common than 不変量.
不変式論は代数幾何学で重要だ。
Invariant theory is important in algebraic geometry.
Both are read ふへん, but 不変 means 'unchanging' while 普遍 means 'universal'. Use 不変 for things that do not change over time, and 普遍 for things that are true everywhere.
不変量 is a technical term. In everyday language, use 不変 or 変わらない to mean 'invariant'.
光の速さは不変である。
The speed of light is invariant.
この規則はすべての場合に普遍的に適用される。
This rule is invariant across all cases.
普遍的な価値観を尊重する。
Respect invariant universal values.