The phrase "a certain conjecture" is correct and usable in written English.
It can be used when referring to a specific conjecture that is not named or is known to the audience in a general sense.
Example: "In the realm of mathematics, a certain conjecture has sparked much debate among scholars."
Alternatives: "a particular conjecture" or "a specific conjecture".
Nevertheless, no one has ever been able to prove or disprove a certain basic conjecture about pi: that every digit has an equal chance of appearing in pi.
Certain conjectures of the dual-process theory have subsequently been verified in a variety of invertebrate and mammalian brain systems [ 17- 30].
Certain conjectures about human memory are keys to the central idea.
Certain conjectures, concerning the behaviour of systems mathematical models, in connection with mathematical methodologies of control synthesis operating on them, are finally stressed.
This conjecture says that after a certain point in the sequence a digit drops out completely.
It provides a conjectural explicit reciprocity law for a certain element associated to an abelian extension of a totally real number field whose existence is predicted by earlier conjectures of Rubin and Stark.
Some claim that his family name was Quixada, or Quexada, for there is a certain amount of disagreement among the authors who write of this matter, although reliable conjecture seems to indicate that his name was Quexana.
On her attitude to partying, there's still a conjecture about clubbing Juliana doesn't get: "People who associate clubbing with a certain age, I'm like, you can all have babies and retire at 45. That's not really my personality so… whatever".
However, it is acceptable to conjecture that the close contact region of cell adhesion can be seen with a certain darker region as well.
The Fisher–Hartwig conjecture describes the asymptotic behaviour of the determinants of then×nToeplitz matricesDn(c)=det[ci−j]n−1i, j=0for a certain class of functionsc.
