生成一個SQL查詢，以獲取數學成績高於90分的學生名單。 
Here is an example of SQL query that can be used to retrieve the list of students with a math grade higher than 90:

```SQL
SELECT student_name
FROM grades
WHERE math_grade > 90;
```

Note: This query assumes that the student names and math grades are stored in a table named `grades`, in columns named  `student_name` and `math_grade`, respectively. The specifics of the query, such as table and column names, may need to be adjusted to match the schema of the actual database it is being run against.