Does Repentance Expiate False Oaths?
Question

I heard that the one who swears a false oath (Yameen Al-Ghamus) will be immersed in Hell, and that there is no expiation for it. Does this mean that there can be no repentance from this sin? 
Will Allah forgive all sins if the repentance is sincere?
Praise be to Allah.What is Al-Yamin Al-Ghamus?
Al-Yamin Al-Ghamus refers to a false and evil oath in which a person unlawfully consumes the property of another. It is called Ghamus (lit. immersing) because it immerses the one who does that in sin and then in Hell. (Ibn Al-Athir in An-Nihayah, 3/724) 
Secondly: 
It says in Al-Mawsu`ah Al-Fiqhiyyah (35/41): 
“The jurists differed concerning the necessity of expiation in the case of a false oath . There are two points of view: 

It is not obligatory to offer expiation for a false oath . This is the view of the majority of jurists: the Hanafis, Malikis and Hanbalis. 
It is obligatory to offer expiation for a false oath . This is the view of the Shafi`is.  

Each group offered evidence to support its view.” (See: Bada’i` Al-Sana’i, 3/3; Al-Taj wAl-Iklil, 3/266; and Kashf Al-Qina`, 6/235)
It says in Fatawa Al-Lajnah Al-Da’imah (23/133): 
“Al-Yamin Al-Ghamus is a major sin, for which no expiation is sufficient because it is such a grave sin. No expiation is required for it according to the more correct of the two scholarly opinions; rather what is required is repentance and prayers for forgiveness.” 
Whether one says that expiation is required or not, the expiation does not expiate the sin of a false oath. Rather it is essential to repent sincerely. 
Hence Shaykh Al-Islam Ibn Taymiyah said in Majmu` Al-Fatawa (34/139), after mentioning the difference of scholarly opinion concerning expiation for a false oath: 
“But they agreed that the sin is not erased merely by offering expiation.”
Does repentance expiate false oaths?
A false oath, like other sins, may be expiated by sincere repentance . There is no sin for which repentance cannot be accepted, for Allah has opened the door of repentance to every sinner , and Allah accepts the repentance of the one who repents. 
Allah says (interpretation of the meaning): 
“Say: O My slaves who have transgressed against themselves (by committing evil deeds and sins)! Despair not of the Mercy of Allah, verily, Allah forgives all sins. Truly, He is Oft-Forgiving, Most Merciful.” [Az-Zumar 39:53]
Ibn Kathir (may Allah have mercy on him) said:  
“This verse is a call to all sinners, disbelievers and others, to repent and turn to Allah. It tells us that Allah forgives all sins for the one who repents from them and turns away from them, no matter what they are, no matter how many they are, even if they are like the foam of the sea. There are many verses on this topic.”
And Allah knows best.