SQL To Fetch Partition Boundaries and Filegroups For a given partition scheme name, I need to retrieve the set of


Boundary Value
FileGroup Name


This must work without the existence of any tables participating in the scheme.

i.e. joins via sys.indexes will not work.

I think the answer lies around sys.destination_data_spaces, but have not yet figured the joins to sys.partition_range_values.
This relationship isn't altogether intuitive but I think this query will get you what you need:

SELECT 
  PScheme       = ps.name, 
  PFunction     = pf.name,
  Boundary      = dds.destination_id,
  BoundaryValue = prv.value,
  [Filegroup]   = fg.name
FROM sys.partition_schemes AS ps
INNER JOIN sys.partition_functions AS pf
        ON ps.function_id = pf.function_id
INNER JOIN sys.destination_data_spaces AS dds
        ON ps.data_space_id = dds.partition_scheme_id
INNER JOIN sys.filegroups AS fg
        ON dds.data_space_id = fg.data_space_id
LEFT OUTER JOIN sys.partition_range_values AS prv
        ON dds.destination_id = pf.boundary_value_on_right + prv.boundary_id 
       AND prv.function_id = pf.function_id;


And because LEFT/RIGHT is always a tedious mental exercise for me, it might be that you need to flip the boundary_value_on_right part on the second-last line:

ON dds.destination_id = prv.boundary_id + ABS(1-pf.boundary_value_on_right)  


You don't need to have created any tables.