(g), (h) and (i) of this section, if such objection to a claim is made, the court, after notice and a hearing, shall determine the amount of such claim as of the date of the filing of the petition, and shall allow such claim ... in such amount ... 11 U.S.C. § 502(b). 10 . See In re UAL Corp., 310 B.R. 373, 377 (Bankr.N.D.Ill.2004) (“It has long been recognized that one of the essential, 'core' functions of bankruptcy is the allowance or disal-lowance of claims against the debtor's estate, without regard to the source of the claim.”); United States v. Rhodey (In re R & W Enters.), 181 B.R. 624, 643 (Bankr.N.D.Fla.1994) ("The process of claim determination and payment is within the exclusive province of the bankruptcy court.”); In re Chateaugay Corp., Ill B.R. 67, 71 (Bankr.S.D.N.Y.1990) (<HOLDING>); In re Bar M Petroleum, 63 B.R. at 346 ("By
holding that when a creditor files a proof of claim the bankruptcy court has core jurisdiction to determine that claim even if it was a prepetition contract claim arising under state law holding that a proceeding that by its nature could arise only in the context of a bankruptcy case is a core matter subject to the jurisdiction of the bankruptcy court recognizing that restructuring of debtorcreditor relations is at the core of bankruptcy court power and that the court has jurisdiction to allow disallow liquidate and estimate aspects of claims based on contract law holding that bankruptcy court may issue proposed findings and conclusions in a core proceeding over which the bankruptcy court does not have constitutional authority holding that a motion to enforce bankruptcy sale order is a core proceeding and citing 11 usc  105a as the section which gives the bankruptcy court the power and the jurisdiction to enforce its valid orders 